Center for Energetic Concepts Development, Department of Mechanical Engineering, University of Maryland

Modeling and Simulation

1. A Density Functional Theory of the Reaction of TNT with Sulfate Radical
WANG Guo-qing, WU Yu-kai, HOU Qing-wei, ZHOU Yan-xia, ZHOU Zhi-ming
School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing 100081, China

Abstract: Using the density functional theory (DFT) and Gaussian 03 package software, the reaction mechanism for the TNT with sulfate radical reaction was studied. The geometries of all the molecules reactants, transition states and products were optimized and the harmonic vibration frequencies and the energies were calculated at the level of B3LYP/6-31G(d). The changes of geometry and stability of reaction process was analyzed. The experimental and calculated results show that the reaction of sulfuric radical with TNT was mainly controlled by dynamics and the major channel of hydrogen abstraction was the reaction of TNT-methyl hydrogen and sulfate radical, meanwhile the major channel of addition reaction was the reaction of non-substituted TNT-phenyl carbon and sulfate radical.

2. Numerical Simulation on Influence of Shell on Fuel Near-field Dispersal Velocity
ZHOU Bao-shun1, 2, WANG Shao-long2, LUO Yong-feng2, NIU Li-bo1, HU Jian2, LIU Zhi-yong2
1. The Second Artillery Engineering College, Xi'an 710025, China
2. The Second Artillery Arming Institute, Beijing 100085, China

Abstract: Based on the AUTODYN program, the fuel near-field dispersal velocity of FAE was simulated. The fuel dispersal velocity curve under explosive load, the initial and maximum fuel dispersal velocity were obtained. The simulation results perfectly accorded with those gained from theoretical calculation. The results showed that the smaller the yield strength and thickness of outer shell, the higher the fuel dispersal velocity. For the inner shell, the factor of density should also be considered besides the yield strength.

3. Effects of NH_3 and ClO_3 on the Initial Pyrolysis of 1, 3, 5-Trinitro-1, 3, 5-triazine
XU Wen1, 2, ZHAI Gao-hong1, 2, DING Li3, JIANG Fu-ling1, 2, SUO Bing-bing1, 2, WEN Zhen-yi1, 2
1. Key Laboratory of Synthetic and Natural Functional Molecular Chemistry of Ministry of Education, Xi'an 710069, China
2. College of Chemistry & Materials Science /Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Northwest University, Xi'an 710069, China
3. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The structures of 1, 3, 5-trinitro-1, 3, 5-triazine (RDX) and its complexes with the pyrolysis products (NH3, ClO3) of ammonium perchlorate (AP) were optimized by the B3LYP/6-31g(d) method, and the bond dissociation energies of N-NO2 for RDX and its complexes were calculated. The results show that the geometrical configurations of the RDX in the complexes are similar to the RDX structure, but the original CS symmetry of RDX is destroyed. The axial nitryls of RDX in the complexes with NH3, ClO3 are prior to the equatorial nitryls in its pyrolysis process and there are trivial changes on the N-NO2 bond dissociation energies when RDX combines with NH3 and ClO3. However, once the complexes decompose, the product NO2 can react with NH3 more easily. This exothermic reaction may induce the subsequent pyrolysis process of RDX.

4. Effects of Ammonium Nitrate on CO Concentration in Combustion Gas of a Gun Shooting Guided Missile Propelling Charge

HE Zeng-di, Lü Zhi-xing, YUAN Zhi-lei, YANG Li, XIAO Zhong-liang
Department of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China

Abstract: The CO concentration in combustion products of propellant with different ammonium nitrate content was calculated by using minimum free energy method. The effects of ammonium nitrate on CO concentration in propellant combustion gas of a gun shooting guided missile propelling charge are investigated by means of closed-bomb-gas chromatography used in lab scale investigation and on-line IR used in gun operation. Tests results show that adding ammonium nitrate in gun propellant can increase the oxygen balance of propelling charge, also can reduce CO concentration in combustion gas of propelling charge and can reduce CO peak concentration. In particular condition, adding ammonium nitrate in gun propellant can effectively reduce the phenomena of exhausting carbon monoxide poisonous gas.

5. A Method of Computing/Determining the Kinetic Triplet of the Exothermic Decomposition Reaction of Energetic Materials from Peak Temperature and Conversion Degree at Tp of DSC Curves
HU Rong-zu1, 3, ZHAO Feng-qi1, GAO Hong-xu1, ZHAO Hong-an2, ZHANG Hai3
1. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2. College of Communication Science and Engineering, Northwest University, Xi'an 710069, China
3. Department of Mathematic/Institutes ofData Analysis and Computation Chemistry, Northwest University, Xi'an 710069, China

Abstract: A method of computing/determining the kinetic triplet [E, A and f(α)] of the exothermic decomposition reaction of energetic materials was presented from peak temperature(Tp) and conversion degree at Tp(αp) of DSC curves under different constant heating rate conditions. Using this method, the kinetic triplet of the exothermic decomposition reaction of 2, 6-bis(trinitromethyl)-4, 8-dinitro-glycoluril, 1, 4, 5, 8-tetranitro-1, 4, 5, 8-tetrazadelin and bis(1, 3-dinitro-1, 3-diazacyclohexanone-2) was obtained.

6. Numerical Simulation on Fluctuation Value of Volume Flow Rate for the Inside Layer of the Variable-burning Rate Propellant
GAO Ke-zheng, MA Zhong-liang, XIAO Zhong-liang
Chemical Industry and Ecology Institute, North University of China, Taiyuan 030051, China

Abstract: Three-dimensional flows of variable-burning rate propellant solution in the screw are simulated using the POLYFLOW in different operating conditions. Simulation results indicate that the volume flow rate of core material is directly proportional to the screw velocity. When the screw velocity is different, the high frequency fluctuation values of the volume flow rate are between 0.02% and 0.03%. The fluctuation values of the volume flow rate are directly proportional to the fluctuation values of the screw velocity. The volume flow rate of the core material are directly proportional to the entrance pressure. When the entrance pressure is different, the high frequency fluctuation values of the volume flow rate are between 0.024% and 0.026%. The fluctuation values of the volume flow rate rapidly increase with the entrance pressure increase, when the fluctuation value of entrance pressure is greater.

7. Theoretical Study on Structure, Heat of Formation and Detonation Properties of Picrate-based Energetic Ionic Salts
LI Zhi-min1, YAN Ying-jun2, JI Hui-ying1, ZHANG Jian-guo1, ZHANG Tong-lai1, YANG Li1
1. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
2. Jiangxi Journalism and Publication College, Nanchang 330224, China

Abstract: The DFT-B3LYP method was employed to optimize the molecular geometries of five kinds of picric energetic ionic salts:ammonium;aminoglycoluril;carbohydrazide;aminoguanidinl;diaminotetrazole. Their IR vibration frequency and heat of formation were investigated. Based on the heat of formation, the detonation properties(detonation velocity and detonation pressure) of the title compounds were estimated from the Kamlet-Jacobs equation.

8. Molecular Simulation of Effect of Aluminum Powder Oxidation on Interface Adsorption for HTPB
JIAO Dong-ming, YANG Yue-cheng, QIANG Hong-fu, WU Wen-ming
Xi'an Hi-Tech Institute, Xi'an 710025, China

Abstract: In order to explore the effect of aluminum powder oxidation on interface properties for binding agents of HTPB propellant, molecular dynamics method(MD) and COMPASS force field were adopted to simulate the adsorption energy and mechanical properties(elasticity coefficient, moduli and poisson ratio) of the interfaces constructed by HTPB, Al and Al2O3. By analyzing adsorption energy and pair correlation function, the essence of interface interaction was elucidated. Simulation results showed that the rigidities of Al and Al2O3 were weaken and the elasticity was strengthened after coating with HTPB. The adsorption energy of HTPB on Al2O3 crystal faces is far more than on Al crystal faces. The interaction of HTPB/Al interface is composed of Vdw action, while the interaction of HTPB/Al2O3 is mainly related to static action.

9. Safety Analysis on Truing Process of Solid Propellant by Finite Element Method
LI Jun, ZHAO Xiao-bin, WANG Chen-xue, GUAN Hong-bo, CHENG Li-guo, CHENG Xin-li, WANG Ning
Research Center of Solid Propellant Safety Technology of Aerospace Industry, Xiangfan Hubei 441003, China

Abstract: In order to study the hazard point of truing process, the truing process of solid propellant was predicted by a thermalmechanical coupled finite element method. Based on the viscoelastic integral constitutive relation, the rules of temperature response of truing process caused by pressure and friction were obtained, and the hazard point was calculated. The results showed that the temperature in solid propellant truing process increases with increasing of truing velocity, and the maximum temperature in solid propellant truing process could attain up to 65℃ when the truing velocity was 10mm/s. There was no remarkable temperature change for the maximum temperature under the truing thickness of 1.0mm, 1.5mm and 2.5mm. The hazard area in truing process was on the surface of solid propellant scraps rather than the cutter edge.

10. Experiment Study and Numerical Simulation of Shock Wave Generated by Thermobaric Column Exploding in Limited Space
CHEN Hao, TAO Gang, PU Yuan
College of Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The connected limited and limitless space are designed and the propagation characteristics of shock wave that generated by thermobaric column exploding in limited space is tested. The overpressure curves in different distances are obtained by experiment and numerical simulation. The results show that the overpressure curve of limited space has many peaks, which is different from overpressure curve of limitless space that has only one peak. This phenomenon is caused by the structure of limited space. Through three-dimensional numerical simulation using LS-DYNA software, the propagation process in different distances are analyzed. The numerical results are in agreement with the experimental results.

11. Cylinder Test of Aluminized Explosives and Its Numerical Simulation
HAN Yong, HUANG Hui, HUANG Yi-min, LU Xiao-jun
Institute of Chemical Materials, CAEP, Mianyang Sichuan 621900, China

Abstract: Power abilities of two aluminized explosives with diameters of 50 mm and 100 mm were studied by cylinder test and the relationships between expansion distance and time were gained. Using the finite element hydrodynamic code LS-DYNA, the cylinder tests of two aluminized explosives were simulated and the Lee-Tarver ignition and growth trinomial model was adopted. The parameters of JWL equation of state about detonation products of aluminized explosives and the Lee-Tarver ignition and growth reactive flow function were obtained by comparing the simulation results and test results, which could be reproduced accurately the cylinder tests of two aluminized explosives. The calculated result reveals the expansion process of the cylinder wall driven by the later released energy of aluminized explosives can be imaged very good by the Lee-Tarver ignition and growth reactive trinomial model.

12. A Density-Functional Theoretical Investigation, Thermodynamic Properties and Adiabatic Time-to-Explosion of ATO
HU Yin1, MA Hai-xia1, LI Jun-feng1, SONG Ji-rong1, 2, HU Rong-zu3
1. School of Chemical Engineering, Northwest University, Xi'an 710069, China
2. Conservation Technology Department, The Palace Museum, Beijing 100009, China
3. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The theoretical investigation on 4-amino-1, 2, 4-triazol-5-one(ATO) as a structure unit was carried out by using density functional theory(DFT) method at the B3LYP/6-311G**level, and the population analysis and the stability was also discussed. The specific heat capacity of ATO was determined with continuous Cp mode of microcalorimeter(Micro-DSC Ⅲ). The relationship between the specific heat capacity of ATO and the thermodynamic temperature Cp=1.482 915-6.209 699×10-3T+1.699 017×10-5T2(Jg-1K-1) and the standard molar specific heat capacity of ATO of 114.18 Jmol-1K-1 in 298.15 K were obtained. According to the relationship between specific heat capacity and thermodynamic functions: enthalpy, entropy, Gibbs free energy of ATO in the range from 283 K to 353 K, relative to the standard temperature 298.15 K, were calculated. Using the relationship between Cp and T and the thermal decomposition parameters, adiabatic time-to-explosion of ATO was also evaluated to be 408.05 s.

13. Molecular Simulation of Effect of Bonding Agents on Interface Interaction for HTPB and Al/Al_2O_3
JIAO Dong-ming, YANG Yue-cheng, QIANG Hong-fu, WU Wen-ming
Xi'an Hi-Tech Institute, Xi'an 710025, China

Abstract: The molecular dynamics method and COMPASS force field were adopted to simulate adsorption energy and mechanical properties of the interfaces constructed by HTPB, bonding agents and crystal faces of Al and Al2O3. The results show that the adsorption energy of bonding agents on Al2O3 crystal is more than that of HTPB on Al2O3 crystal, while the adsorption rule on Al crystal is not distinct. The adsorption energy of bonding agent(TEA) and HTPB on Al2O3 crystal faces is far more than that on Al crystal faces. The(001) surface of Al has the greater adsorption energy than that of(011) surface, while the(010) surface of Al2O3 has the greater adsorption energy than that of(001) surface. The higher the adsorption energy, the better the mechanical property. The effect of bonding agents on mechanical properties(tensile modulus) of adsorption system decreases in the order: TAZTEAMAPOHACMAPOHX-752.

14. Properties Prediction of Picryl Furazan Ether Compounds
LAI Wei-peng1, GE Zhong-xue1, QIU Shao-jun1, LIAN Peng1, XUE Yong-qiang2
1. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2. Applied Chemistry of Taiyuan University of Technology, Taiyuan 030024, China

Abstract: In order to obtain high energy density materials with good properties, picryl furazan compounds with oxy bridges were designed. These compounds were picryl(3-nitrofurazan-4) ether(FOP), bis(3-nitrofurazan-4) picryl ether(DFOP) and tri(3-nitrofurazan-4) picryl ether(TFOP) . The densities of formation, enthalpies, detonation properties and stabilities of these compounds were calculated by B3LYP/6-31G method, Kamlet formula and experiential formula of H50. The results show that, the density, enthalpy of formation and detonation property of obtuse picryl compounds increased when introducing nitrofurazan unit to the compounds. The stabilities of furazan compounds can be improved when introducing picryl to the compounds.

15. Theoretical Studies of Interreaction of Complex System Nitroglycerin-Polymer Binder
FAN Xiao-wei, JU Xue-hai, SUN Xiao-qiao, XIAO He-ming
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: Geometrical structures of the supermolecular systems of nitroglycerin(NG) with polyethylene glycol(PEG), hydroyl-terminated polybutadiene(HTPB), glycidyl azide polymer(GAP), poly(3-azidomethyl)3-methyl-oxetane(AMMO) and poly(3, 3-bis(azidomethyl)-oxetane)(BAMO) were optimized by the semiempirical molecular orbital theory PM3 method. Binding energies, after corrections for dispersion energies, were approximately obtained. The binding energies of five complex systems are-49 kJ/mol to-60 kJ/mol as polymerization degree n=4. When the polymerization degree increases, with the exception of NG with GAP and BAMO, the strengths of the intermolecular interactions of complex systems increase. In the complexes, the shortest intermolecular contacting distances between two submolecules of the complexes are 0.270 nm to 0.340 nm.

16. Study on Software of Solid Propellant Burning Rate Prediction Based on one-dimensional Steady-state Reaction Gas Flow
FENG Feng, CHEN Jun, ZHENG Ya, SONG Hong-chang
School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: Based on the model of one-dimensional steady-state reaction gas flow, the correction factors of burning rate related to double base propellant, modified double base propellant and composite solid propellant were summed up, the application scope of theoretical combustion model was broadened. Using Visual C++and Microsoft Access for the development tools, the software of solid propellant burning rate prediction(SPRS) was completed by the structural parameters of chemical bonds. The software was based on system of Windows XP, user-friendly, easy to use, and with the functions of data updating and information querying. The burning rates and pressure indexs could been calculated when the chemical compositions of the propellant(formula) and the pressures were given. The compositions of the propellant(formula) could be adjusted by giving the burning rates and pressure indexs too. It was of great significance in development of cycle-shortening and cost-saving of solid propellant.

17. The Interior Ballistic Model and Numerical Simulation of Multilayer Gun Propellant Charge
ZHANG Jiang-bo, ZHANG Yu-cheng, JIANG Shu-jun, YU bin, YANG Yan
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The interior ballistic mathematics model of multilayer propellant charge was established based on the classical interior ballistic theory and the interior ballistic process of 59 model 100 mm gun was calculated with the simulating program compiled by MATLAB. The calculated results indicate that on the assumption that each layer charge with propellant SF-3, propellant D, propellant GN, propellant SD, when the layers of multilayer charge from one to four, the muzzle velocity increas 3%, 3.63%, 3.69;when the ratio of each layer burning rate is 1∶1.4∶1.8∶2.2, the ratio of each layer thickness is 5.5∶1.5∶1∶2, the max pressure is 306.4 MPa, the muzzle velocity is 932.4 m/s, then the muzzle velocity increasing 3.69% and keeping the max pressure invariable, it is in evidence that the pressure platform effect. Considering the interior ballistic and the feasibility on the technique, it is very effective that adopting three layers on the multilayer charge. For multilayer charge, with a certain weapon, there is only one relation between the ratio of each layer burning rate and the ratio of each layer thickness, the keeping invariable max pressure and the most muzzle velocity increasing.

18. The One-dimensional Interior Ballistic Aerodynamic Model and Numerical Simulation of Traveling Charge
YANG Jing-guang1, 2, YU Yong-gang2
1. The First Aeronautical Institute of Air Force, Xinyang Henan 464000, China
2. Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: In order to resolve design of the solid traveling charge in interior ballistic, an advance one-dimensional interior ballistic aerodynamic model of the projectile is established. Taking into account the changed quality of projectile, a numerical simulation of the structural parameters of the traveling charge in interior ballistic process of 30mm artillery is performed by the MacCormack format. The space pressure distribution curve of traveling charge at all times after the shell is obtained. The pressure distribution curve are analyzed and compared with that for the regular charge. By analyzing the distribution of pressure on space after the shell and the shooting results, showing that under the conditions of the same charge, projectile weight and max pressure, in comparison with the regular charge, traveling charge has faster muzzle velocity and higher pressure and can improve the promoted efficiency of interior ballistic.

19. Numerical Simulation of the Diffraction Detonation Wave Based on the Modified SPH Method
ZHOU Jian-hui, SUN Xin-li, GAO Weiran, HAN Ya-wei, NIE Hu
The Second Artillery Engineering Institute, Xi'an 710025, China

Abstract: To investigate the non-ideal propagation of detonation waves in the spherical shell of the charge containing a metal spherical body, based on the modified SPH method, a simulation of detonation waves′propagation is figured out, and a simple engineering approximate calculation method is given to compute the propagation time of waves in the metallic spherical shell of charge. The results show that the characteristic detonation time obtained by simulation is consistent greatly with that obtained by theory analysis, indicating the modified SPH method is feasible and rational for explosion numerical simulation.

20. Effect of Oxygen Balance of Propellant on Muzzle Flash
HE Zeng-di, LIU You-ping, HE Li-ming, XIAO Zhong-liang
School of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China

Abstract: The combustible gas concentration in combustion products of propellant with different oxygen balance was calculated by using minimum free energy method. The combustible gas composition of the propellant concentration was analyzed by closed-bomb and gas chromatography. The photographs of muzzle flash were taken by high speed camera. The area, diameter and photo density of muzzle flash on photographs were analyzed. The results show that with rising the propellant oxygen balance the combustible gas concentration and the area, the diameter and the photo density of muzzle flash are reduced. In particular condition, increasing oxygen balance of propellant can effectively reduce muzzle flash phenomena.

21. Theoretical Calculation on the Thermodynamic Properties for the Combustion Products of Propellant
XU Yang-sen, LU Zhuan, WANG Ming-liang, TIAN De-yu, LIU Jian-hong
School of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen Guangdong 518060, China

Abstract: The thermodynamic properties for the combustion products of the rocket propellants, chloride and fluoride of Cu、Pb、B、Al, were studied in detail by using density functional theory(DFT) at B3LYP/6-311G(d, p) and B3LYP/SDD levels. Thermodynamic properties of diatomic molecules were calculated by statistical mechanical method based on Morse potential in the range of 300K to 6000K. The results show that the values of heat capacity and entropy obtained from Morse potential approach for CuF, PbF, PbCl, BCl, ClO, AlCl, AlF and BF diatomic molecules are in good agreement with reference data with the deviation of 1%-2%, indicating that the statistical mechanical method based on Morse potential can be used to calculate the thermodynamic properties for the combustion(diatonic products molecules) of the rocket propellant conveniently.

22. Numerical Simulation of Two Dimension Shock Initiation and Detonation Behavior of PBX
LIANG Zeng-you1, HUANG Feng-lei2, ZHANG Zhen-yu3, WANG Hui1
1. School of Mechatronice Engineering, North University of China, Taiyuan 030051, China
2. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
3. National University of Defense Technology, Changsha 410073, China

Abstract: A reaction rate function model built up based on KIM model is applied to analysis damage influence on initiation and detonation behavior of PBX. Reaction rate function model parameter is obtained by genetic algorithms. And validation of the model is verified by comparing simulation results with Forest-Fire model. Two dimension numerical simulation of PBX is executed to explosive′s initiation and detonation process by embedded the new reaction rate function model into finite element analysis program. Numerical simulation results are in good agreement with experiment results of damaged explosives shock initiation and detonation behaviour. The new reaction model can be used to analyze detonation mechanism of damaged explosive while porosity and grains size is changed by impact load.

23. Density Functional Theory of Intermolecular Interactions of Aza-calix[4]arene with RDX
HOU Su-qing, CAO Duan-lin, ZHANG Wen-yan, LIU Sheng-nan
College of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China

Abstract: The optimized geometries of four complexes of aza-calix[4] arenas1～4 and RDX are obtained with density functional theory method at the B3LYP/6-31G(d) level. The intermolecular interaction energy is calculated with basis set superposition error correction(BSSE) and zero point energy correction(ZPE) and compared. The interaction energies dominantly from hydrogen bonds. Natural bond orbital(NBO) analysis is performed to reveal the origin of the interaction. The calculated results of the intermolecular interaction energy show that tetra-aza-calix[2]-m-diamido-arene[2]-2-amido-1, 3, 5-tri-azine is better to eliminate RDX from explosive waste water.

24. Investigation of Density, Detonation Velocity and Impact Sensitivity of Aromatic Nitro-compounds by Quantum Chemistry and QSPR Method
LAI Wei-peng1, LIAN Peng1, WANG Bo-zhou1, GE Zhong-xue1, ZHANG Zhi-zhong1, XUE Yong-qiang2, PANG Xian-yong2
1. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2. Department of Applied Chemistry, Taiyuan University of Technology, Taiyuan 030024, China

Abstract: Thirty-two different descriptors were calculated by Gaussian98 and other programs on the basis of structure-properties. The relationships between the density, detonation velocity and impact sensitivity of aromatic nitro-compounds and the descriptors were established by quantitative structure-property relationships(QSPR) method in Cerius2 program package, and the correlative coefficient were 0.951, 0.992 and 0.923, respectively. The average errors between the estimated and experimental values were 1.92, 0.93 and 5.10 percent, respectively. The detonation velocities calculated by QSPR and Kamlet method were compared, and it was obvious that the veracity of the former is higher than that of the latter. Furthermore, the factors which mainly affect the density, detonation velocity and impact sensitivity and which increase the density, detonation velocity, but decrease the impact sensitivity of aromatic nitro-compounds were discovered.

25. Effect of Pore Shape on the Deformation Characteristics under the Lauch Load
XIANG Cong, ZHANG Qi
State Key Laboratory of Explosion Science and Technology, BeijingInstitute of Technology, Beijing 100081, China

Abstract: In order to investigate the effect of the deformation process of interior pore of warhead under the lauch load on the safety of gun propellant, a numerical simulation is carried out by ANSYS/LS-DYNA software. The results show that there is little difference to elliptical and spherical pore with the same volume for the deformation characteristics.

26. Molecular Simulation on Plasticizer Migration in the Bond System of HTPB Propellant
LI Hong-xia, QIANG Hong-fu, WU Wen-ming
The Second Artillery Engineering Institute, Xi'an 710025, China

Abstract: To overcome the disadvantage of experimental means, the molecular models of plasticizer and the bond system were constructed. The compatibility and the diffusibility of dioctyl sebacate(DOS) in the bond system of hydroxyl terminated polybutadiene(HTPB) and isophorone diisocyanate(IPDI), were investigated by molecular simulation method under the COMPASS(condensed-phase optimized molecular potentials for atomistic simulation studies)force field. The solubility parameters of components were calculated by amorphous cell dynamics method and the compatibitity of DOS with HTPB and IPDI was judged. The results show that: DOS is well compatible with HTPB and IPDI, which is in good agreement with the conclusion of compatibility drawn by the bind energy gained by blend method. The diffusion coefficient of DOS in the bond system of HTPB and IPDI by the simulation method of molecular dynamics is 1.2×10-7cm2s-1.

27. Study of Strength of Base Bleed Charge in Projectile Shot
ZHANG Hong-lin1, 2
1. School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
2. Qingyang Chemical Industry Corporation, Liaoyang Liaoning 111002, China

Abstract: In order to study the strength of the base bleed charge in projectile shot, the mathematic model and the strength condition under load and stress of the base bleed charge in projectile shot were established based on strength theory. The reason causing the base bleed charge be destroyed was analyzed from the force state and the strength condition. The results show that the increa of the stress is the main reason causing the base bleed charge to be destroyed.

28. Relationship between the Impact Sensitivities and Aromaticity for Nitroanilines Explosives
DU Jun-liang1, 2, SHU Yuan-jie1, 2, ZHOU Yang2, WANG Ping3, YIN Ming2, LONG Xin-ping4, ZHU Zu-liang4
1. School of Materials Science and Engineering, Southwest University of Science and Technology(SWUST), Mianyang Sichuan 621010, China
2. Institute of Chamical Materials, CAEP, Mianyang Sichuan 621900, China
3.Graduate Department of China Academy of Engineering Physics, Mianyang Sichuan 621900, China
4. CAEP, Mianyang Sichuan 621900, China

Abstract: Geometry optimizations and frequency calculations were carried out for five nitroaniline explosives by means of density functional theory(DFT). Vibrational analyses show that the optimized structures have no imaginary frequencies, which indicate that the structure of each molecule corresponds to a local minimum on the potential energy surface. The aromaticity index HOMA and NICS values were calculated and the relationship between the impact sensitivity and aromaticity was studied. Results show a good linear correlation between them. Increase of the ring aromaticity accompanied by an increase in the respective impact sensitivities. This study demonstrates that the aromaticity can be used to evaluate the impact sensitivity of explosives.

29. Numerical Simulation on Factors Affecting Ignition Characteristics of A New Engine
LU Wei1, JIANG Jian-jun2, ZHANG Qun3
1. Xi'an Insititute of Electromechanical Information Technology, Xi'an 710065, China
2. The PLA General Staff′s Army Aviation Burean and Work in the Xi'an Delegate Office, Xi'an 710077, China
3. College of Power and Energy, Northwestern Polytechnic University, Xi'an 710072, China

Abstract: The mechanism of deflagration to detonation transition(DDT) of liquid octane/air mixture in an one-dimention sealed space was studied and a model program was developed by using theory of one-dimension reacting flow, particle-trajectory model dual-step reaction model and computer-programming technology, The effect of detonation wave ignition energy and initial temperature of liquid power on the structure and development of detonation wave was studied. The results show that the detonation intensity rises with ignition energy but decreases as initial temperature increases. The numerical results are in good agreement with experimental ones, indicating that the method and program developed is feasible.

30. Application of 2D Viscous CE/SE Method in Numerical Simulation of Explosion Field with the Gear Wave Wall
LI Xin1, WENG Chun-sheng2
1. School of Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
2. National Key Lab of Transient Physics, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: Flows of blast waves with gear wave wall around the explosion point is simulated numerically by using two-dimensional viscous CE/SE method. The rule of interaction between blast waves and gear wave wall is analyzed. Pressure contours which can clearly show the transformation of shock structure are obtained. Numerical results show that blast waves reflect or pass around the gear wave wall. By comparing with the explosive field without gear wave wall, the cut effect of a gear wave wall on explosion in air is analyzed. More analyses about pressure far field under the influence of the height or thickness of gear wave wall have been done. Numerical simulation results can be contributed to the research of the protection in the explosive field.

31. Analysis about Progressive Combustibility of Variable Burning-rate Gun Propellant Based on Closed-bomb Test Data
ZHANG Li-hua, XIAO Zhong-liang, Lü Bing-feng, LIU You-ping, MA Zhong-liang, HE Zeng-di, HE Li-ming
School of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China

Abstract: In order to further investigate the progressive combustibility of variable burning-rate gun propellants, a mathematic physical model to describe the energy releasing regularity of gun propellant based on closed-bomb test data is put forward. The progressive combustibility of a variable burning-rate nitroamine gun propellant which has a center hole and double layer was studied through closed-bomb test. The results show that the presented mathematic physical model can be used quantitatively to estimate the strength of progressive combustibility of gun propellant;this developed nitroamine gun propellant exhibite progressive combustion feature and its progressive combustibility can be controlled by adjusting its formulation and physical dimension.

32. Numerical Simulation on the Influence Factors of Boron Particle Ignition in Solid Propellant Ramjet Environment
WU Wan-e1, 2, PEI Ming-jing2, GUO Er-ling1, ZHAO Peng1, MAO Gen-wang2
1. Section 503 of the Second Artillery Engineering Institute, Xi'an 710025, China
2. College of Astronautics, Northwestern Poly-technical University, Xi'an 710072, China

Abstract: The boron particle ignition in solid propellant ramjet environment was numerically simulated with revised Williams combustion model. The influences of environment temperature, the species and concentration of oxidizer, particle radius and the oxide layer thickness on boron ignition were analyzed. The caculated results show that, the ignition delay time and ignition time decrease with the increase of environment temperature or the increase of H2O vapor pressure. The ignition delay time increases with the increase of O2 pressure. The increase of boron particle radius makes oxide thickness increase, and ignition time and ignition delay time prolong.

33. Simulated Analysis on Interior Ballistic of Sequential Charge
ZHANG Jiang-bo, JIANG Shu-jun, YU Bin
Xi'an Modern Chemistry Research Institute, Xi'an, 710065, China

Abstract: Based on the classical interior ballistic theory, a mathematics model of sequential charge was founded. With the simulating program compiled by MATLAB, one small-bore weapon were simulated. The effect of different charge weight, spout diameters and igniting time on the p-t curves and v-t curves were simulated and analysed. The calculated results show that for the subsidiary charge weight there is an ideal value with which the efficiency of the subsidiary charge will be maximum;for the spout diameters there is a threshold value, up or down that value the muzzle velocity will decrease;for the igniting time there is a certain value, the efficiency is best with changeless maximum pressure. Adopting suitable subsidiary charge weight and spout diameters and precisely controlling the igniting time is the key to achieve the pressure platform at the maximum pressure.

34. Establishment of the Primary Combustion Model of Fuel-rich Solid Propellant with Agglomerated Boron Powder
XU Hui-xiang, ZHAO Feng-qi
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: In order to study the effect of agglomerated boron powder on the energy release and burning rate characteristics of boron-based fuel-rich solid propellant, the physical and mathematical combustion models of this propellant were established based on the experimental analyses and BDP model. The combustion surface of the model makes up of two parts, agglomerated boron powder and conglomeration regions of AP, HTPB binders. The AP flame and final flame conglomeration regions are formed in gas phase, and the binder of agglomerated boron powders participates in pervasion flame and final flame. On the assumption that agglomerated boron powder is an inert substance in primary combustion, the mathematical model of fuel-rich solid propellant with agglomerated boron powders is put forward. By predigesting the AP/HTPB and agglomerated B/AP/HTPB system, the SAP/S expression of burning rate formulation is deduced. The effect of the volume fraction ζ1 of agglomerated boron powders on the combustion surface of propellants is considered adequately in the model, and the volume factor of agglomerated boron powders is introduced to the mathematical model. The model can reasonably explain the main combustion characteristics of this propellant.

35. Molecular Simulation of Cellulose-based Energetic Binders
HUANG Rui, YAO Wei-shang, TAN Hui-min
School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China

Abstract: Performances of nitrocelluloses(NC) and nitric acid ester of cellulose glycidyl ether(NGEC) were calculated by molecular simulation in COMPASS forcefield using Synthia module of Materials Studio. The results that are in agreements with the theories and experiments indicate that molecular simulation by Synthia module is practicable in qualitative analysis of the system. Properties of azidodeoxycellulose(AC), azidodeoxycellulose glycidyl ether(ACGE), azidodeoxycellulose nitrate(ACN) and nitrocellulose azidonitrate glycidyl ether(NCAGE) were predicted by Synthia modules. The effects of different degree of substitution and different groups on properties of those binders were analysed. Predicting data show that ACN and NCAGE are high energetic binders with better mechanical and processing properties.

36. Theoretical Study on Effect of Tetrazine Structures on Their Thermal Decomposition Mechanisms
XIONG Ying, SHU Yuan-jie, WANG Xin-feng, ZONG He-hou, ZHOU Yang, YIN Ming
Institute of Chemical Materials, CAEP, Mianyang Sichuan 621900, China

Abstract: The thermal decomposition trajectories of s-tetrazine molecule and its five derivatives were simulated by ab initio molecular dynamics(AIMD) method to acquire the possible decomposition pathways and identify their relative importance. The reaction channels were studied by density functional theory(DFT) at B3LYP/6-311G(d, p) level to locate the local minimum points and the transition structures, and to verify the result of AIMD in terms of energy, suggesting that s-tetrazine molecule underwent concerted triple dissociation, just as its photolysis mechanism. The effect rules of five different substituents on the modes of tetrazine ring opening, the stability of the tetrazine ring and thermal decomposition mechanism of tetrazine derivatives were obtained. If the stability of the substituent is better than that of the tetrazine ring, decomposition occurs first through the ring breaking. Otherwise, the substituent reactions first take place. Moreover, some new conclusions about the effect of intermolecular reaction on the thermal decomposition mechanisms of tetrazines were achieved.

37. Numerical Simulation on the Kinetic Energy Increase of Aimed Warhead
LIANG Zheng-feng, YUAN Bao-hui, SUN Xing-yun, LIU Hui-ling, LIU Han-hui, WANG Juan-juan
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The course of fragments droving by explosives in aimed warhead controlled by detonating meshwork and ordinary fragmentation warhead was studied by means of numerical simulation, and dynamic picture of this course and some interrelated data were obtained with the help of the data processing of numerical simulation results, the velocity and density distribution of fragments about aimed warhead controlled by detonating meshwork and the increases of velocity, consistency and kinetic energy of fragments about aimed warhead controlled by detonating meshwork relative to ordinary fragmentation warhead were obtained.

38. Creep Model of PBX Based on Modified Time Hardening Theory and its Application
TANG Wei1, 2, LI Ming1, PANG Hai-yan1, ZHANG Qiu1, ZHAO Xiao-dong1
1. Institute of Chemical Materials, CAEP, Mianyang Sichuan 621900, China
2.Graduate School of CAEP, Mianyang Sichuan 621900, China

Abstract: A creep model based on modified time hardening theory is promoted to simulate the short duration creep behavior of PBX components.15 groups model parameters are determined by using data from 15 uniaxial compressive creep tests of a type of PBX based on HMX. Simulated parameters of 3 groups are used to build an initial creep model which is validated by ANSYS simulation software. The universal parameters of the creep model are determined based on the principle of little probability event of assumed normal probability distribution. The creep model is employed in simulating the creep deformation of a HMX based PBX components subjected to vac-sorb forces in one hour. The results from numerical simulation and theoretical analysis show that the modified time hardening creep model is suitable for short duration creep behavior of PBX.

39. Study on the Structures and Properties of FOF-18 by Quantum Chemistry
GE Zhong-xue1, LAI Wei-peng1, LIAN Peng1, WANG Bo-zhou1, XUE Yong-qiang2
1. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2. Applied Chemistry of Taiyuan University of Technology, Taiyuan 030024, China

Abstract: The molecular geometry of FOF-18 was optimized by the B3LYP method with basis set 6-31G. The steady geometric configuration was obtained. The infrared vibrational frequencies and the IR spectrum of the system were obtained on the basis of vibration analysis. The density was estimated theoretically by the Monte-Carlo method, and the enthalpy of formation was estimated by designing reactions which have equal bonds and equal electronic pairs. The detonation velocity, detonation pressure and detonation heat were estimated by the Kamlet formula. The estimated properties were compared with those of CL-20. The results show that the total molecule of FOF-18 was like letter "N" and there were 7 strong absorbing apices. The density, enthalpy of formation, detonation velocity, detonation pressure and detonation heat of FOF-18 are 2.06 g/cm3, 501.03 kJ/mol, 9411.82 m/s, 42440.76 MPa and 6637.46 kJ/kg, respectively. The properties of FOF-18 is similar to that of CL-20.

40. Theoretical Calculation of C-N Bond Dissociation Energies for [60] Polynitrofullerene
TAN Bi-sheng1, PENG Ru-fang1, 2, LI Hong-bo1, JIN Bo1, CHU Shi-jin1, 2
1. College of Material Science and Engineering, Southwest University of Science and Technology, Mianyang Sichuan 621010, China
2. Institute of Chemical Materials, CAEP, Mianyang Sichuan 621900, China

Abstract: The C-N bond dissociation energies, averaged C-N bond dissociation energies and averag nitryl binding energies of fourteen kinds of [60] polynitrofullerenes were calculated with the PBE density functional theory method. It is found that the C-N bond dissociation energies range from 137.14 to 158.51 kJ/mol, averag C-N bond dissociation energies range from 168.56 to 177.78 kJ/mol and averag nitryl binding energies range from-40.47 to-50.92 kJ/mol, respectively. It showed that the C-N bond dissociation energies vary little when nitryls increased from two to eight. The 1, 2 mode precedes to the 1, 4 mode, and the symmetry of [60]polynitrofullerene contributes to C-N bond dissociation energies negligibly.

41. Establishment of an Optimized Failure Probability Model of Solid Rocket Motor and its Application
GAO Ming
Navy Equipments Management Office, Beijing 100000, China

Abstract: Through the failure rule analysis of deposited solid rocket motor, an optimized failure probability model was established based on the combination of exponential distribution and Weibull distribution, and was used to calculate life reliability of naturally deposited solid rocket motor. The calculated results show that the calculated storage life using optimized model agree well with the actual condition, and a new practical calculated method is provided for life reliability of deposited solid rocket motor.

42. The Mathematical Model of Propellant Actual Combustion Law on the Constant Volume Condition
Lü Bing-feng, LIU You-ping, DONG Feng-yun, MA Zhong-liang, HE Zeng-di, XIAO Zhong-liang
Department of Chemistry and Environment, North University of China, Taiyuan 030051, China

Abstract: The correctional mathematical model of propellant combustion on the constant volume condition is established for studying propellant actual combustion law. The influence of distribution and variety of web thickness, non-synchronous ignition, burning rate coefficient changing, etc. On propellant actual combustion law were analyzed. On the basis of these analyses, the propellant actual combustion process was simulated by the correctional mathematical model including comprehensive factors. The calculated results have better consistency with experimental results, showing that the hypothesis and scheme established by correctional mathematical model is reasonable.

43. Molecular Dynamic Simulation of the Crystallization of HNIW
CHEN Hua-xiong1, CHEN Shu-sen1, JIN Shao-hua1, LI Li-jie1, SHI Yan-shan1, XIANG Yu-lian2
1. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China;
2. Institute of Chemical Defence, PLA, Beijing 102205, China

Abstract: Through the simulation of the growth of ε-hexanitrohexaazaisowurtzitane(HNIW) crystal and the attachment of additive to certain crystal face, the specified additive by the simulation modifies the morphology of ε-HNIW into a more regular morphology. The morphology of ε-HNIW was simulated with molecular dynamic simulation using the constructed crystal cell. T1, T2 and T3 were selected as the additives to modify the morphologies of ε-HNIW crystal by the aid of the molecular dynamic simulation. In the recrystallization experiments, additives T1, T2 and T3 differently modified the morphologies of ε-HNIW crystal, which were consistent with the results predicted with molecular dynamic simulation. The results show that molecular dynamic simulation is available for the precdition of the influence of additive on the growth of ε-HNIW crystal and with the aid of the simulation, the additive that can modify the crystal into more regular morphology can easily be chosen.

44. Prediction on Densities of Polynitroaromatic Compounds via Boosting Algorithm
ZHANG Hai1, 2 WANG Yao2, CHEN Bing2, HU Rong-zu3, GAO Hong-xu3, ZHAO Feng-qi3
1. Department of Mathematics, Northwest University, Xi'an 710069, China
2. Institute for Information Science and System Sciences, Xi'an Jiaotong University, Xi'an 710049, China
3. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The densities of polynitroaromatic compounds(PNACs) are predicted by Boosting algorithm. The molecular structure describers(MSD) are used as input feature parameters. The results show a better correlation between the densities and molecular structures of PNACs. Compared with artificial neural network, the Boosting algorithm greatly improves the prediction accuracy with the relative errors of predicted results within 8%.

45. Structures and Stabilities of N_5~+、N_5~-、N_8、N_(10) by Density Functional Theory (DFT) Method
LIAN Peng1, LAI Wei-peng1, WANG Bo-zhou1, GE Zhong-xue1, XUE Yong-qiang2
1. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2. Applied Chemistry Department of Taiyuan University of Technology, Taiyuan 030024, China

Abstract: In order to investigate the structural characteristics and stability of some typical polynitrogen compounds in molecular level, such as N+5, N-5, N8 and N10, the structures of them were optimized by B3LYP method on 6-31G(d, p) basis set. The steady geometric configurations and molecular orbits were obtained. The stabilities were analyzed, finding that the structures of N5+, N-5, N8 were V-type, pentazole ring and metastable cubical crystallite, respectively. The chemical stability of N-5 was better than that of N+5 and the chemical stability of N10 was better than that of N8.

46. The Quantum Chemical Investigation on the Nucleophilicity of UDMH
LI Zheng-li, WANG Xuan-jun, ZHANG You-zhi
Second Artillery Engineering University, Xi'an 710025, China

Abstract: In order to study the nucleophilicity difference between-NH2 and-N(CH3)2 of unsymmetrical dimethylhydrazine, full geometrical optimizations of UDMH have been carried out by RHF, DFT/B3LYP, MP2 and semiempirical methods. The predicted structure parameters are compared to the experimental ones. On the basis of equilibrated geometrical structure obtained by B3LYP/6-311G method, the nucleophilicity of-N(CH3)2 and-NH2 groups are investigated by electrostatic potential and MO calculations. The calculated nucleophilicities are compared to the experimental results of the reaction of UDMH with halohydrocarbon. The calculated results of nucleophilicity by MO are in agreement with the experimental results, showing that the nucleophilicity of-N(CH3)2 is stronger than that of-NH2.

47. Experiments and Numerical Simulation of Isochronous Core Igniter
WANG Pei1, CHEN Lang1, FENG Chang-gen1, XIANG Yong2, ZHANG Ming2, ZHANG Zhong-xin3, HUANG Ze-lin3
1. State Key Laboratory Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
2. Institute of Chemical Material, CAEP, Mianyang Sichuan 621900, China
3. Shanxi North Jindong Chemical Industry Co. Ltd, Yangquan Shanxi 045000, China

Abstract: In order to enhance the simultaneity of gun ignition, a kind of isochronous gun igniter with the detonation waves as the ignition stimulation was fired. The pressure vs. Time curves at different positions of ignition-tubes were measured. The flame turbulence, isochronous ignition and increasing gas products were considered in the calculation. A calculation modeling was given to simulate the burning in the gun igniter. The 3D simulation of the burning in the gun igniter was conducted by CFD software. The calculated curves of pressure versus time in the ignition-tube were compared with experimental curves. The results indicate that the ignition-tube has good synchronism, and the calculated pressure curves are in agreement with the experimental curves in reasonable range.

48. Molecular Dynamics Simulation of Young′s Modulus and Solubility Parameter of Azide Thermoplastic Elastomers
LI Qian, YAO Wei-shang, TAN Hui-min
School of Material Science and Engineering, Beijing Institute of Technelogy, Beijing 100081

Abstract: To investigate the mechanical properties of azide elastomer and its compatibility with nitrate esters, Young′s modulus of azide polyurethane thermoplastic elastomer composed of different soft and hard segments, cohesive energy density, and solubility parameter of azide elastomer and nitrate esters were calculated by molecular dynamics simulation method. The results show that the miscibility of azide thermoplastic elastomer with nitrate esters were contrary to their mechanical properties. That is to say, when the mechanical properties were better, their compatibility with nitrate were worse.

49. Molecular Dynamics Simulation of Elastic Properties on RDX Crystal at Different Temperatures
ZHU Wei, XIAO Ji-jun, MA Xiu-fang, ZHANG Hang, XIAO He-ming
Molecule and Material Computing Institution, Chemical Engineering Institute, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: In order to explore the change rule of static mechanical properties of cyclotrimethylene trinitranmine(RDX) with temperature, periodic simulation calculation at NPT ensemble in multi-temperatures is carried out with molecular dynamics method and compass force field. Their elastic coefficients, moduli, Poisson′s ratios were obtained from analysis of static machanics. The results show that in the temperature range of 195K to 345K, with increasing temperature, the elasticity and flexibility of RDX decrease. When the temperature rise to 345K, the elasticity and flexibility of RDX remain almost unchanged.

50. A Molecular Dynamics Simulation of Mechanical Properties of Polyethyleneoxide, Polytetrafuran and Their Copolyether
XIAO Ji-Jun1, ZHU Wei1, XIA Lu2, FAN Jian-Fen2, XIAO He-Ming1
1. Molecule and Material Computing Institution, Chemical Engineering Institute, Nanjing University of Science and Technology, Nanjing 210094, China
2. Chemistry and Chemical Engineering Institute, Soochow University, Suzhou 215123, China

Abstract: In order to search for theoretical method used to predict mechanical properties of composites and to provide fundamental information for pre-polymer of adhesives for NEPE propellants, NVT molecular dynamics simulations of polyethyleneoxide(PEO), polytetrafuran(PTHF)and their copolyemer poly(ethyleneoxide-co-tetrafuran) [P(E-CO-T)] were performed under the compass force field and the elastic constants, and poisson′s ratios, moduli and Cauchy pressure were calculated. It is found that the rigidity and ductibility of PEO is the best and P(E-CO-T) is better than that of PTHF.

51. Interactions between BTTN and Polymer Binders
SUN Xiao-qiao, FAN Xiao-wei, JU Xue-hai, XIAO He-ming
Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The supermolecular systems of 1, 2, 4-butanetriol trinitrate(BTTN) with polyethylene glycol(PEG), hydroyl-terminated polybutadiene(HTPB), glycidyl azide polymer(GAP), poly(3-azidomethyl)-3-methyl-oxetane(AMMO) and poly(3, 3-bis(azidomethyl)-oxetane)(BAMO) were calculated by semiempirical molecular orbital theory PM3 method.Geometrical structures were optimized. Binding energies were approximately obtained with dispersion energies being corrected. Binding energies(absolute value) of BTTN with HTPB and AMMO increase as the molecular chain of polymers increase. However, there is a difference from the above rule of binding energies of BTTN with BAMO, GAP, PEG with increasing the molecular chain. Meanwhile, binding energies of BTTN with GAP, AMMO and BAMO are slightly larger than those of BTTN with two other polymer binders(PEG and HTPB).

52. Fractal Numerical Simulation for Turbulent Chemical Reaction
ZHANG Jian-wen1, WANG Yan-fei2
1. School of Economics and Management
2. School of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China

Abstract: The fractal model(FM) of turbulent chemical reaction is developed based on the phenomenological concept of vortex cascade and fractal theory. The numerical simulation of the Steckler′s room fire is carried out with the fractal model of turbulent combustion chemical reaction and the eddy-dissipation-concept(EDC) model by CFD software-ANSYS CFX 10.0. The two equations κ-ε turbulent model with buoyancy modification is used and Rosseland radiation model is applied to take radiation into consideration. To validate FM model, comparisons and analysis are made for fire scenarios of Steckler. Comparisons are also made with the numerical simulations from other combustion models including the eddy dissipation model and the eddy break-up model for the same fire experiments. The results show that the temperature and velocity distribution using FM simulation give better results illustrating FM is a promising mathematical model for turbulent chemical reaction.

53. Prediction on Density of Aromatic Polynitro Compounds via the Artificial Neural Networks
CAI Hong-hua, TIAN De-yu, LIN Zhen-tian, LIU Jian-hong, HONG Wei-liang
College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen Guangdong 518060, China

Abstract: The densities of a series of aromatic polynitro compounds are predicted via an artificial neural network(ANN) based on erroneous reversed dissemination method. The results show a better correlation between the densities and molecular structures of aromatic polynitro compounds. Selecting molecular structure describers(MSD) as input characteristics parameters, a better predicted accuracy is obtained. The relative error between the predicted values and literature ones of the densities of aromatic polynitro compounds is within ±l0%.

54. Comparision of Different Quantization Methods for Calculating the Structure of β-HMX
WANG Ai-ying, CHEN Shu-sen, LI Li-jie, JIN Shao-hua, KONG De-bin
School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081, China

Abstract: Using Gaussian 98 packages software, the structure of β-octahydro-1, 3, 5, 7-tetranitro-1, 3, 5, 7-tetrazocine(HMX) has been optimized at the level of HF/6-31G, DFT-B3LYP/6-31G and MP2/6-31G, respectively. The structure of β-HMX, such as bond length, bond angle, dihedral angle, is analyzed theoretically. Comparison of the experimental and calculated results show that the calculated values of β-HMX at the level of B3LYP/6-31G accord with the experimental one obtained by X-ray diffraction experiment. The effects of B3LYP/3-21G, B3LYP/6-31G, B3LYP/6-31++G, B3LYP/6-311++G and B3LYP/6-31++G** methods on the calculated results of β-HMX are small, showing that the calculated results at the level of B3LYP/6-31G can meet the optimization of β-HMX structure. The atom charges and the energies of frontier molecular orbitals of β-HMX at different levels are also calculated. Results obtained by B3LYP method in which electron correlation effect has been sufficiently considered are very reasonable.

55. Propagation Characteristics of TATB Based Explosive Detonation Wave in Bigplate Test
LI Zhi-peng1, HUANG Yi-min1, LONG Xin-ping2, ZHANG Zhen-yu3, LI Ze-ren4
1. Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang Sichuan 621900, China
2. China Academy of Engineering Physics, Mianyang Sichuan 621900, China
3. Institute of Applied Physics, National University of Defence Technology, Changsha 410073, China
4. Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang Sichuan 621900, China

Abstract: In order to investigate the propagation characteristics of TATB based explosive detonation wave under the point initiation condition, a double sensitivity VISAR system is used to measure the copper plate velocity in Bigplate test, and a two-dimensional hydrodynamic code DYNA2D is applied to simulate detonation waves in TATB based explosive. The results indicate that the pressure profiles show two dimensional structure and the detonation wave propagation transfers from axial direction to radius direction. The measured free surface velocity of copper plate agree well with calculated values.

56. Prediction of the Impact Sensitivity of Explosives by Quantumchemical Parameters
WANG Guo-dong, LIU Yu-cun
Department of Environment and Security Engineering, North University of China, Taiyuan 030051, China

Abstract: The fully optimized geometries and the vibrational analysis of 10 aromatic and 26 heteroaromatic explosive molecules were carried out by B3LYP/6-31G* method. The quantum-chemical parameters were obtained and two traditional parameters(oxygen balance index and active index) were analyzed. The results indicated that the lower unoccupied molecular orbital energy(Elumo) is an important factor affecting the impact sensitivity(H50)of aromatic explosives. For prediction of the impact sensitivity of aromatic explosive, the model established by multiple linear regression with Elumo and the two traditional parameters is better than that established with the two traditional parameters, showing that considering the effects of Elumo on H50 may increase the effect of predicting the impact sensitivity.

57. Theoretical Calculation of the Detonation Parameters of New Furazan(furoxan) Explosives
LIANG Qin-qin1, 2, WANG Jun2, HUANG Yi-gang2
1. Department of Chemistry, College of Materials, Southwest University of Science and Technology, Mianyang Sichuan 621010, China
2. Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang Sichuan 621900, China

Abstract: A series of new furazan(furoxan) explosive molecules were designed with 3, 4-bis(aminofurazano)furoxan(BAFF) as structural unit. The detonation parameters of this kind of explosive were calculated by BW rule for predicting explosive decomposition products, Rothsteine′s method for estimating detonation velocity and Cooper method for estimating C-J pressure. And the calculated detonation parameters were compared with those of HMX and other explosives. The results show that the explosives designed are high-energy density material compounds with high density. Their detonation velocity and detonation pressure are between those of TATB and HMX. As furazan ring in the molecules have aromacity, these explosives molecules are predicted of favorable stability.

58. Three Dimensional Numerical Simulation of Detonation Wave Propagation on Corner-turning of Composition B
HE Yang-yang1, 2, LONG Yuan1
1. Engineering Institute of Engineering Corps, PLAUST, Nanjing 210007, China
2. The 63956 Army of PLA, Beijing 100093, China

Abstract: In order to study the propagation characteristics of detonation wave and low pressure flow field in the corner-turning after the detonation of composition B, the numerical simulation program LS-DYNA3D has been used to simulate the detonation wave propagation phenomena of three specific corner-turning(120°, 90°and 45°) charge structures. The spread process of detonation wave through corner-turning is observed, changes of detonation velocity when wave front overpass the corner-turning are discussed. The results show that when the detonation wave spread at the corner-turning, an attenuation-growth process caused by the changes in the diffuse acreage is formed. The greater the corner-turning degree of charge, the more stable when detonation wave passed. With the reduction of the corner-turning degree, the wave-front pressure, detonation velocity and ability of detonation of corner-turning all gradually decrease.

59. Application of Artificial Neural Network in Predicting the Density of Explosives
WANG Guo-dong, LIU Yu-cun
Department of Safety and Environment Engineering, North University of China, Taiyuan 030051, China

Abstract: The fully optimized geometries and the vibrational analysis of 16 kinds of explosive molecules were calculated by the density functional theory(DFT) method at the B3LYP/6-31G* level. The calculated quantum-chemical parameters were analyzed. The results indicated that the parameters(the average of polarizability, the average of quadrupole moment and the dipole moment) have better correlation with density. The prediction model of density was created by artificial neural network(ANN) and three parameters as descriptor. The results obtained from the model indicated that, the most relative error between the predicted values with literature ones of density is 6.6% and the least relative error is 0.47%, showing that the ANN is feasible to predict the density of explosive.

60. Technical Approaches of Enhancing the Energy of Boron Based Fuel-rich Propellant
WANG Li-jun, SUN Xiang-yu, LI Xue-jun, CHU Qiang, YANG Wei, WU Yue
Inner Mongolia Synthetic Chemical Engineering Institute, Huhehot 010010, China

Abstract: The energy levels of two sorts of boron based fuel-rich propellant, HTPB/AP/B and BAMO-THF/AP/B compositions, have been calculated with special thermodynamics code. It is showed that the specific impulse of the two propellants will both increase with increasing the boron contents in propellant formulations while the AP contents are decreasing and the contents of other ingredients are fixed simultaneously, and the specific impulse of HTPB propellant is higher than that of BAMO-THF propellant while the other ingredients except the binder in both propellants are consistent. According to the calculated results, the baseline formulation of boron based fuel-rich propellant has been established to carry out motor tests. It is indicated that the spurt injection efficiency of boron based fuel-rich propellant in spout of gas generator can reach 98% while adding 5%-8% magnesium powder to the baseline formulation. Fine boron powder and compound F have the function of enhancing the combustion efficiency of boron based fuel-rich propellant and accordingly improving the specific impulse in motor test. The specific impulse of fuel-rich propellant containing compound F3 and boron powders(particle size 2μm) has reached 9502Nskg~(-1) in ducted motor flight simulation test.

61. Numerical Simulation on Blast-Induced Plastic Compression and Shear Damage in Rock Blasting
WANG Zhi-liang~1, HUANG Jing-zhong~2, FAN Shu-qun~1, WANG Jian-guo~3
1. College of Engineering Science, University of Science and Technology of China, Hefei 230027, China
2. College of Environmental and Hydraulic Engineering, Zhengzhou University, Zhengzhou 450002, China
3. Tropical Marine Science Institute, National University of Singapore, Singapore 119260)

Abstract: In order to well calculate the blast-induced plastic compression and shear damage, based on the randomicity of rock strength distribution of representative volume elements and the theory of continuum medium damage mechanics, a damage-softening statistical constitutive model is introduced and is then incorporated into the commercial FEM software, LS-DYNA. The compression and shear damage caused by the spherical and cylindrical explosions in infinite rock mass are numerically simulated. Information is obtained on the stress-strain relationship at different confining pressures and damage distribution at different times. This damage model of rock material with less constitutive parameters can favorably exhibit the characteristics of damage and softening.

62. Numerical Simulation of Shaped Charge Jet
WANG Jian-hua, ZHANG Hui-suo
North University of China, Taiyuan 030051, China

Abstract: The numerical simulation and contrast analyses for the process of shaped charge jet produced by the liner of different cone angle and the same kind of explosives and the liner of same cone angle and the different kind of explosives are performed by means of the ANSYS/LS-DYNA 3D software. The results show that the shaped charge jet formed by the liner of 53° is short and thick and the shaped charge jet formed by the liner of 43° is long and thin. Higher speed jet can be formed by high energy explosive. This result is in accordance with the mature theory, proving the correctness of numerical simulation model and parameters used in the state equation. This work provides a basis for designing and developing new shaped charge products, and reducing the experiment cost and the development time of new products.

63. Prediction of Burning Rate of HTPB Propellant by Artificial Neural Network Model
LIU Jian-min~(1, 2), TANG Shao-chun~3, XU Fu-ming~1, ZHOU Wei-liang~1
1. Institute of Chemical and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
2. Xi'an North Huian Chemical Industrial Lt. Co., Xi'an 710302, China
3. Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China

Abstract: Using the existing burning rate test data of RDX/AP/Al/HTPB propellants containing nano-structure Fe_2O_3 catalyst, an artificial neural network(ANN) model based on back propagation(BP) arithmetic was built to predict the burning rate of this type of propellant, and the nonlinear relation between the content of catalysts in propellants and its burning rate was simulated. As the results, the network structure was ascertained to be the type of 3-4-1, the learning rate and momentum constant were 0.75 and 0.45 respectively, and the mean square error of network arithmetic converged to 1.0×10~(-4) after 56910 iterations. The burning rate of HTPB propellant containing nano-structure Fe_2O_3 catalyst was predicted by the trained network model, and the output of this model had good agreement with the experiment data, there was only one with larger relative error(-9.19%) among prediction values, the other prediction values all had the relative error less than 3.5%. It was suggested that the built network model has the preferable ability in aspects of remembrance and forecast to predict the burning rate of above mentioned propellants.

64. Density Functional Theoretical Investigation on 3, 4-Dinitrofurazanfuroxan(DNTF)
MA Hai-xia~1, 2, SONG Ji-rong~1, XIAO He-ming~2, HU Rong-zu~3, ZHAO Feng-qi~3
1. College of Chemical Engineering/Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Northwest University, Xi'an 710069, China
2. Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, China
3. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Molecular orbital calculations were performed at the density functional theory(DFT) B3LYP/6-31+G(d) level to investigate the conformations and properties of 3, 4-dinitrofurazanfuroxan(DNTF). From the geometry and natural charges analysis, the oxygen atom of O14 was considered to have much influence on the structure and properties of the title compound. The IR frequencies and the NMR chemical shifts were also calculated which is in good agreement with those of the experimental results. The frontier orbital composition analysis indicate that the main compositions of HOMO are C(7)s, C(2)s, C(3)s, C(6)s, C(6)p, O(14)p and C(2)p and those of LUMO are C(7)s, C(16)s, C(7)p, N(11)p.

65. Investigation on the Thermal Safety of Solid Rocket Motor
LI Gao-chun~1, YUAN Shu-sheng~1, YUAN Song~2
1. Department of Aircraft Engineering, Naval Aeronautical Engineering Institute, Yantai Shandong 264001, China
2. The Navy Missile Motor Representation to Xi'an, Xi'an 710025, China

Abstract: The heat transfer through the case and liner of a solid rocket motor to the outside of the propellant grain was simulated numerically by use of the thermal conductivity equation with source term. The characters of propellant combustion by the action of environmental heat source were analyzed and the critical temperature of thermal hazard and the delay time of ignition were obtained. The results show that the heat transfer process of solid rocket motor subjected to the outside heat source can be simulated numerically by use of the thermal conductivity equation with chemical source term. The critical temperature of propellant is 520～525K and the delay time of ignition decreases with increasing the outside flame temperature.

66. Numerical Simulation of the Influence of Initial Porosity Random Distribution on the Performance of Interior Ballistics
FENG De-cheng~(1, 2), WENG Chun-sheng~2, BAI Qiao-dong~2, WEI Wei~2
1. College of Mathematics and Information Science, Northwest Normal University, Lanzhou 730070, China
2. School of Power Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The formula describing the function relations of the initial porosity versus place under two especial configurations in local charged guns is presented. Considering as a balanced random process and combining one-dimensional two-phase flow model of interior ballistics, the random process and some statistic distribution in guns are simulated by Monte-Carlo method. The statistical regularity of the random change of initial porosity affecting the performance of ballistics is studied. The results show that the effect of different configurations on pressure wave is most obvious but is little on maximum pressure and velocity in same charged guns.

67. Theoretical Study on Intermolecular Interactions of Tetrazole-water Dimers
ZHOU Su-qin, JU Xue-hai, XIAO He-ming, FAN Xiao-wei
Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: Tetrazole monomers(Ⅰ, Ⅱ), water(Ⅲ) and all their possible stable dimers(Ⅳ, Ⅴ, Ⅵ and Ⅶ) are fully optimized at the DFT-B3LYP/6-311++G~(**) level. Vibrational frequencies were calculated to ascertain that each structure was characterized to be the stable structure(no imaginary frequencies). The basis set superposition error(BSSE) at B3LYP/6-311++G~(**) level are 3.95, 2.52, 2.57 and 4.03 kJ/mol for Ⅳ, Ⅴ, Ⅵ and Ⅶ, respectively. The zero point energy(ZPE) corrections for the interaction energies are 7.00, 5.27, 4.04 and(5.93 kJ/mol) for Ⅳ, Ⅴ, Ⅵ and Ⅶ, respectively. After BSSE and ZPE corrections, the greatest corrected binding energy of tetrazole-water dimers is-37.68 kJ/mol. The charge redistribution mainly occurs on the adjacent N-H…N atoms of tetrazole dimers between submolecules while the change of the charge among two submolecules is small for all four tetrazole-water dimers. Natural bond orbital(NBO) analysis is performed to reveal the origin of the interaction.

68. Theoretical Study on C-NO_2 Bond Effected by Intramolecular Amidos
ZHANG Chao-yang, SHU Yuan-jie, DONG Hai-shan, HUANG Yi-gang
Institute of Chemical Material, China Academy of Engineering Physics. Mianyang 621900, China

Abstract: C-NO_2 bonds effected by intramolecular amidos of variable positions and quantity were studied systematically at B3LYP/6-31G~(**) level. The results indicated that:In amino and nitro substitutes of alkanes, effects on C-NO_2 bond were inductive effects and spatial effects occurred by amido and nitryl, and changed into feebleness as they separated more than 2 carbon atoms away. In amino and nitro substitutes of ethene, amidos on No.1 position weakened C-NO_2bond and No.2 strengthened it with a result: the more amidos, the shorter C-NO_2 bond, the more electro-negativities on carbon atom of C-NO_2 bond, the longer C=C bond, the more τ. That is, it became more obvious that there were function of affording electrons in amidos and conjugated effect in entire molecule. In amino and nitro substitutes of 1, 3-butadiend, effects on C-NO_2 bond occurred by amidos were kin to orientation effects on benzene ring when H-bonds were not formed by H atoms in amidos and O atoms in nitryls; the effects mentioned above would be weakened when H-bonds formed (the more H-bonds, the more weakened), at same time, C-NO_2 bond would be weakened.

69. Analysis and Assessment on Theoretical Calculation Methods for the Velocity of Explosive-Driven Flyer Plate
HAN Xiu-feng, YAN Nan, CAI Rui-jiao
Disasters, Beijing Institute of Technology, Beijing 100081, China

Abstract: Six methods to calculate the velocity of explosive-driven flyer plate are introduced and analyzed from literature investigation. The application case of each calculation method is pointed out. The Gurney formulas and several improved formulas for solving some problems existing in the Gurney formulas application are discussed, including effective charge quantity, different air gap distance, different m_c/m_m ratio, multilayer charge contribution, calculation from detonation velocity, and calculation from explosive characteristic number etc. These methods can supply different formulas for various application cases.

70. Regulation and Optimization of Multibase Propellant Burning Characteristics
Yang Dong Zhao Baochang Fu Hongbe
Nanjing University of Science and Technology, Nanjing 210094)

Abstract: In this paper, a combustion model put forward resently for the multibase propellants is introduced. Based on its numerical method, the influence of propellant chemical composition, including main components and their proportions, on the burning characteristics is studied;the theoretic analyses on the mechanisms of the transfer in the burning rate versus pressure curve and that pressure index is more than 1.0 of the nitramine propellants in certain pressure region are carried on in the view of chemical structure and chemical reaction, and some basic principles of optimization and designation of multibase propellant burning characteristics are proposed.

71. The Conjugate Detonation Model and its Numerical Solution
HU Shao-ming
Xi'an Modern Chemistry Research Institute, Xi'an710065, China

Abstract: In CJ and ZND models, the entropy of detonation products at CJ plane is the minimum among all of possible final states and the system will never attain thermodynamic equilibrium, which does not coincide with the basic principles of thermodynamics. In order to get rid of these shortcomings, a new detonation model, named as conjugate detonation model, has been established, in which thermodynamic equilibrium state is taken as the final state of detonation process. In conjugate detonation model, chemical reaction is initiated by the shock wave front, and the released energy makes the particles of explosion products move in different directions. Every pair of two particles, one moves forward and the other backward, is named as a conjugate pair. Correlating detonation wave propagation with the conjugate pairs appearing in micro-explosion and annihilating in expansion, the conjugate detonation model is established. The conjugate detonation model is derived from conservation and thermodynamic laws without any additional conditions as the CJ assumption. The equations group of conjugate detonation model is close and has unique solution. For ideal gases, the detonation parameters calculated by this model are near to those calculated by CJ-ZND model.

72. Energy and Castibility of DNTF Explosive
WANG Qin-hui, ZHANG Yi-an, JIN Da-yong
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The energy character of DNTF was investigated by theoretical calculation, It is established that the experiential formation between detonation velocity(D) and density(ρ_0) is D=2　171+3651ρ_0. The calculated detonation velocity is 9 243　m/s. The relation between detonation pressure(P) and density(ρ_0) is P=(10.8175)ρ_0~2-0.574. The calculated result is P_(max)=40.01GPa. A high relative power is 172.9% TNT-equivalent. In comparison with the crystal structure of TNAZ, pure DNTF has better crystal structure, compactness and melt castibility, and the loading density is more than 91%TMD. The results indicate that DNTF is a new kind of castable energetic material with high energy density and low melting point.

73. Numerical Simulation of Linear Shaped Charge on Rock Cutting
XIONG Zu-zhao~1, WANG Cheng~2, ZHONG Dong-wang~1
1. College of Science, Wuhan University of Science and Technology, Wuhan430081, China
2. Beijing Institute of Technology, Beijing100081, China

Abstract: Numerical simulation of the formation of metal jet and the process of jet penetration into rock was conducted by using the modified MOCL program to investigate the mechanism, process and dynamic condition of linear shaped charge blast cutting rock. The detonation offspring bloating, charge cover deformation jet formation process at cone angle of 60° and the distribution of jet velocity gradient with cone angle of 60° and 90°were obtained. The distribution figures reveal that the cone angle of 60° cumulative jet speed has the trend of becoming smaller at different time of jets during the process of being stretched, the speed gradient is bigger and the head speed is 4 500 m/s. The cumulative jet head speed of cone angle of 90° is 3 500 m/s, the speed gradient is smaller, the head speed is smaller than that of cone angle of 60°. This is corresponding to the practical physical process. On-the-spot experiments on rock cutting show that simulation results are in agreement with physical phenomena and laws of shaped jet. The physical model and numerical algorithm used for the simulation are reasonable.

74. Effects of Intramolecular Amidos on C-NO_2 Bond in Nitro Compounds
ZHANG Chao-yang, SHU Yuan-jie, ZHAO Xiao-dong, LI Hai-bo, LI Jin-shan, WANG Xin-feng
Institute of Chemical Material, China Academy of Engineering Physics, Mianyang621900, China

Abstract: For the first time, this paper took population of nitryl in nitro compounds molecule as its ability to attract electrons(τ) and a criterion for sensitivity of nitro compounds--the τ more strong, the compounds less sensible. Amino and nitro subsitutes were studied systematically at B3LYP/6-31G~(**) level and the results indicated: the para-amidos can strengthen C-NO_2 bond more than ortho-amidos, but meta-amidos can weaken it when amidos and nitros were in a conjugated system, the effects of amino on C-NO_2 bond mainly were inductive and spatial as they were not in a conjugated system, and these effect will be feeble when the two groups have been separated more than a number of carbon atoms away.

75. Application of the Mathematic Model Method in the Formulation Design of Composite Explosive
WANG Hai-fang, LIU Tian-sheng, WANG Feng-ying
The department of environment and safety engineering, The north china institute of technology, taiyuan, 030051, China

Abstract: On the basis of the problem occurred in the formulation design of composite explosive, the multiple factors affecting the performance of the composite explosive, and the principle of oxygen balance, a mathematic model describing composite explosive under some constraint condition is established. The formulation design of composite explosive is studied with the mathematic model method. The results show that the explosion heat of composite explosive obtained from the model by the excel numerical method, coincides with the experimental result under the conditions of same formulation.

76. Prediction of the Enthalpy of Formation for Non-Aromatic Polynitro Compounds Using Artificial Neural Network
LIU Jian-hong~1, TIAN De-yu~(1, 2), ZHAO Feng-qi~3, HONG Wei-liang~1, HONG Ze-meng~1, LI Ling~1, SUN Hong-yuan~4
1. Normal College, Shenzhen University518060, China
2. National University of Defence Technology, Changsha410073, China
3. Xi'an Modern Chemistry Research Institute, Xi'an710065, China
4. Science and Technology Department, Shenzhen University, Shenzhen518060, China

Abstract: With the help of an improved back propagation algorithm on Artificial Neural Network (ANN) model and molecular structure descriptors as inputted characteristic parameters were used to predict the enthalpy of formation ΔH~0f for non-aromatic polynitro compounds (NAPNCs). The influence of Neural Network parameters and molecular structure descriptors on the calculated results were studied. Satisfactory result was made in the multiple linear regression (MLR) calculation of molecular structure descriptors. The correlation coefficient of MLR equation for 70 samples is 0.9977. The accuracy of the enthalpy of for mation calculated by ANN is higher than reported value in reference. The absolute relative difference between reported and predicted values of ΔH~0f is within 0.10 for most of NAPNCs.

77. Numerical Simulation and Experimental Validation of Chemical Reaction Viscous Turbulent Flow Field in the Nozzle of Liquid Rocket Motor
FEI Ji-you~1, LIU Huan-bing~1, YAO Yu-huan~2, YU Bing-feng~3
1. South China University of Technology510640, China
2. Maoming College, Maoming 525000, China
3. Xi'an Jiaotong University, Xi'an710049, China

Abstract: This paper solves the N-S equation by using two-step difference coupled-implicit MacCormack scheme, numerically simulates the compressible viscous turbulence flow in the nozzle of rocket motor and obtains the parameter profiles that cannot be obtained from the experiments. The results are of practical meaning and are important to the design, improvement of performance and theory exploration of rocket motor. Finally the results of numerical simulation are validated by the experiments of rocket motor.

78. Three-dimensional Finite Difference Model of Simulating the Process of Laser Ignition of Explosive
ZHOU lin, LIU Hong-ming, XU Geng-guang
LAB of prevent and control of explosion disaster, Beijing Technolgy of institute, Beijing100081, China

Abstract: Based on the mechanism of thermal ignition of energetic materials, a three-dimensional finite difference model describing the process of laser ignition of explosive is established. With the help of this method, the growth process of surface temperature of RDX, HMX and PETN samples and composite B ignited by laser beam and contour of temperature in the samples and explosion induction time of samples are obtained by numerical simulation method. The results show that the calculated values of induction time obtained by three-dimensional model are in agreement with the experimental data. The temperature growth mainly takes place in the surface layer of cylindrical sample irradiated by laser. The beam radius and pulse width of laser and absorption coefficient of the investigated samples to laser are some principal factors affecting the ignition energy threshold.

79. Numerical Simulation of Structural Integrity for Solid Propellants under Axial High Overloads
WEI Wei, WANG Ning-fei
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The structural integrity of solid propellants is simulated by dynamic mechanical finite element software under axial high overloads when the distortion of the solid propellant is classified as viscoelastic distortion. The simulating data show that the maximum axial stress and strain locate the contact area of the solid rocket and solid propellant bottom, and the circumferential strain is rather larger though the circumferential and the radial stress are smaller.

80. Free-Energy Minimization Investigation on Combustion of GAP Under Constant Pressure and Adiabatic Condition
WANG Tian-fang, LI Shu-fen
University of Science and Technology of China, Hefei 230026, China

Abstract: The principle of free-energy minimization is used to calculate the properties of combustion of glycidyl azide polymer (GAP) under isotonit and adiabatic conditions such as the combustion temperature and the ratio of products. The calculated results show that there are relatively large numbers of H2(g), CO(g) and C(s) in the combustion products of GAP.

81. Equilibrium Computation of Multiphase Non-ideal System
ZHANG Wen qun, ZHANG Zhen shan
Naval University of Engineering, Wuhan 430033, China

Abstract: For a system at a given temperature and pressure, the Gibbs potential function reaches a minimum value in an equilibrium state. According to this principle and the fundamental relations, the necessary thermodynamic foundations describing the equilibrium state of a system are provided. The minimization of the Gibbs potential function, subject to element and charge conservation constraints, is viewed as a nonlinear constrained optimization problem and solved by the method of SQP(Sequential Quadratic Programming). The mixture temperature is solved by iteration. The method can calculate the complex chemical equilibrium of non-ideal, multiphase, electrolytic or non-electrolytic mixtures. Equilibrium results include temperature, density, and species concentrations as a function of mixture fraction. The method is applied to the equilibrium of Al/NaClO4 mixture.

82. Properties of DNTF-Based Melt-Cast Explosives
WANG Qin-hui
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The possibility of DNTF/TNT mixtures used as the liquid carrier for melt-cast explosives was studied by investigating phase diagram. The energies of DNTF/TNT, DNTF/TNT/HMX and DNTF/TNT/HMX/Al mixtures were calculated and discussed. The results indicated that DNTF-based melt-cast explosives had a bright future and could meet the needs of ammunitions for the higher energy.

83. Numerical Simulation of Sensitivity of Grain Fracture
DOU Lei, WENG Chun-sheng, JIN Zhi-ming
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The first minus pressure difference in pressure time profile of gan chamber is used to describe the intensity variation of pressure wave and to determine charge safety. In this paper, the relation between the degree of grain fracture and the sensitivity of pressure wave is set up. Based on interior ballistics model of two phase flow. The curves of the first minus pressure difference vs. the degree of grain fracture and the maximum breech pressure vs. the first minus pressure difference are given through numerical simulation. The research results show that the degree of grain fracture is a valuable way to evaluate the charge safety.

84. Numerical Simulation for Ignition and Flame-spreading of Modular Charge
ZHAO Yi
Deparment 3 of China North Industries Group Corporation, Beijing 100089, China

Abstract: Based on the experimental studies, the one dimensional two phase flow model was devalued. The ignition process of the modular charges was simulated by using MacCormack differential pattern and R-K method, the computing results were analyzed.

85. Study on Detonation Performance of Industrial Explosives
GAO Da-yuan, LU Chun xu, DONG Hai shan
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The detonation velocity and detonation pressure of rock expanded AN, colliery expanded AN, No.2 rock and emulsion explosives have been measured by polymethyl methacrylate method in this paper, and the detonation parameters and the equilibrium composition of detonation products at C-J state of rock expanded AN and No.2 rock explosives have been computed by means of the VLWR code. It is showed that industry explosives have nonideal detonation character of low detonation velocity and low detonation pressure, and the theoretic values are approximating to experimental results.

86. Quantum Chemistry Studies on Thermal Stabillity and Decompostion Mechanism of Methyl-Azotetrazole
WANG Da-xi, HU Guo-sheng
University of Petroleum, Beijing 102200, China

Abstract: The potential curves of decomposition were calculated fhrongh quantum chemistry method for 1-methy1-5-azotetrazol (1-MAT) and 2-methyl-5-azotetrazole (2-MAT). The activation energies of decomposition are 245.9 kJ/mol and 183.2 kJ/mol respectively. Thermal stability and decomposition mechanism have been studied based on ground and dynamic conditions. The calculated results indicate that the thermal stability of 1-MAT is better than that of 2-MAT. Decomposition of opening ring is taken precedently.

87. Numerical Simulation of Displacements of the Media During Explosive Lining in soil

FENG Chang gen, WANG Hai liang, JING Long
School of Mechano Electronics Engineering, Bei jing Institute of Technology, Beijing 100081, China

Abstract: Explosive lining is simplified as an axisymmetric problem. Using DYNA 2D commercial program, the change of displacements of mortar and soil with time during the explosive lining are analyzed by numerical simulation. The numerical simulation results meet the on site experiment results. Research indicates that mortar and soil could be pressured into a stable lining structure through explosive lining. Free face is one of the important factors influencing shape of the lining shell.

88. Numerical Simulation on the Dimensional Effect of Shock-to-Detonation Transition of Solid Explosives
FENG Chang geng, KE Jia shan, CHEN Lang
School of Mechano Electronics Engineering, Beijing Institute of Technology, Beijing 100081, China

Abstract: The dimension of solid explosives plays an important role in the characteristic of the shock to detonation transition (SDT). The nonlinear finite element code was used to calculate and analysis the dimensional effect of the SDT of JO 9159. The results show that the initiation pressure threshold of JO 9159 decreases along with increasing of the diameter and thickness of the explosives.

89. The Numerical Simulation and Experimental Validation of Viscous Flow Field of Chemical Reaction in 2D Rocket Motor Combustor
FEI Ji you, YU Bing feng, XIA Xue li
Xi'an Jiaotong University, Xi'an 710049, China

Abstract: This paper solves N-S equation by employing the MacCormak two step difference of the implicit coupled point. The combustion process is modeled by 17 specice, 12 step finite rate chemical model. The distribution of flow parameters is presented in combustion chamber. The results agree with the theoretical analysis . Finally the method of numerical simulation is validated by the experiment. The conclusions are of practical meaning and important reference to the design, improvement of performance and exploration of the rock motor.

90. Model Design of Acids Mix and Heat Exchange in NC Technology
REN Xiao li, LIU You zhi
Department of Chemical Engineering, North China Institute of Technology, Taiyuan 030051, China

Abstract: Acids mix and Heat exchange are two key sections in NC production technology, this paper presents a modeling method based on their principles and a realizing process with VB6.0.

91. Optimization of Regression Methods in Ammunition Property Test
WAN Xue ren, WANG Lai fen, XAO Sheng min, YI Fang
The PLA 95856 unit, Nanjing 210028, China

Abstract: When modeling ammunition performance testing, multiple correlatgions ofeten present among parameters, So, to select a good regression method is a very important technique for overcoming the drawbacks due to the multiple correlations. It has been shown that partial least squares regression is a good method that can be adopted.

92. The Estimation of Ultimate Compression Properties by Dynamic Mechanical Analysis
FAN Xi ping, LIU Zi ru, SUN Li xia
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: In this paper, a method used to estimate the ultimate compression strength σ b and the compression ratio λ b by dynamic mechanical properties, which were measured by DMA, was proposed and ANA propellant was used as an example. By using the same horizon shift factors as dynamic modulus master curve, the data of compression strength and compression ratio were perfectly superimpose on storage modulus and storage compliance master curve. The results showed that the deveation of estimating data from testing data was within the range of experimental error.

93. Energetic Level Evaluation of NEPE Solid Propellant Containing Hexanitrohexaazaisowurtzitane(CL-20)
WANG Shen, JIN Shao hua, SHENG Si yuan
Beijing Institute of Technology, Beijing 100081, China

Abstract: Energetic level of NEPE solid propellant containing different ratio of CL 20 and HMX was analyzed with our code based on the minimum free energy method. The effect of CL 20 content changing with other ingredients in the formula on the energetic characteristics was studied. The results show that replacing HMX with CL 20 in NEPE propellant can increase the energy density and improve the oxidizing balance of the binder system. In the case of low Al content formula, the use of CL 20 provides more ample space for formula regulation, which can not only improve the propellant energetic characteristics but also alleviate the contradiction between lowering signature and elevating energetic level of the solid propellant.

94. An Ideal Composite Explosive Model Proposed and Its Application
WANG Ke qiang, SUN Xian zhong
Luoyang Normal College, Luoyang 471022, China

Abstract: Based on the ideal composite explosive proposed in this paper, the quantitative relation between detonation velocity of ideal composite explosive D id and detonation velocity D i and mass fraction W i of pure explosive was discovered, and new method was developed that can be used to predict the detonation velocity of composite explosives. The calculated results showed that the calculated detonation velocities were in good agreement with the experimental data, and the mean relative deviation was 1.90%. Not only can the methods developed in this paper be used to predict the detonation velocity of composite explosives, but can help to study the high composite explosives.

95. Quantum Chemical Studies on S_N2 Reaction of Alkyl Nitrates in Gas Phase
WANG Da xi, XIAO He ming
School of Chemical Engineering University of Petroleum, Beijing 102200, China

Abstract: The S N2 reaction of gas phase for alkyl nitrates was studied by quantum chemical method. By using MINDO/3 program, we have calculated the equilibrium geometry and potential curves of the S N2 reaction and obtained activation energies for a series of alkyl nitrates. The barriers of reaction and substituent effect are discussed.

96. Study of the Safety of Ammunition Stored in Stack
JIAGN Jin-yong, LU Gui-e, CHEN Ming-hua
Ordnance Technology Institute, Shijiazhuang 050000, China

Abstract: The condition of heat self-ignition of Ammunition Stored in stack is investigated numerically. The analysis shows that it is necessary to control temperature and maintain heat transfer.

97. Numerical Computations of Shaped Charge Jet with Reverse Initiation at Liner Base
WANG Li xia, HU Huan xing, SUN Jian
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Jet formations of the shaped charge with a low ratio of length to diameter are simulated by LS DYNA3D code. Simulations with both reverse initiation and normal initiation are performed. Reverse initiation are different with normal initiation in the collapse process and jet velocity. The simulation jet tip velocity with reverse initiation is 8.78 km/s, while with normal initiation it is only 4.86 km/s. The simulation results are in agreements with the experiments. The simulation results provide important data for investigation.

98. Electrostatic Initiating Mathematics physics Model of hot Bridgewire Electric Initiating Explosive Device
Xu Yigen Wei Guanghui Liu Shanghe
Electrostatic Institute of Ordnance Engineering College, Shijiazhuang, 050003

Abstract: Based on electrostatic discharge model and thermal explosion theory, mathematics physics model of ESD acted on hot bridgewire electric initiating explosive device is discussed. According to some initiating rules, bridgewire temperature curve and explosive temperature curve are computed.

99. The Research of the Gunpowder Multi composition Prescription Technology of the Ming Dynasty
XU Xin zhao
University of Science and Technology of China, Hefei 230036, China

Abstract: The article, after exploring new historical data of gunpowder prescription techniques, suggests that the significance of the forming of the gunpowder prescription theory in the Ming Dynasty lies in that it made clear execution's role in gunpowedr and that it lays the theoretical foundation of gunpowder's right proportion. The article also studies the models of the prescriptions of multi composition gunpowder. Besides systematizing the prescriptions of multi composition gunpowder, it analyses seven typical prescriptions in the poem style, and makes simulated experiments according to them, thus makes a deep research on the pharmacological effects of the poisonous medicines in the multi composition gunpowder and explains the principles in prescribing and the mutual relations between medicines.

100. Numerical Study on the Whole Process of Explosive Dispersal for Forming Liquid air Cloud
DING Jue, LIU Jia cong
School of Chemical Eng., NUST, Nanjing 210094, China

Abstract: The numerical simulation on the forming of fuel air cloud was presented in this paper. Because of the complexity, the dispersal process was divided into two regimes. For the near field regime, a one dimensional uniform phase model was proposed to depict the motion of detonation product and liquid fuel ring, by using a method of moving boundary to treat moving outer boundary. For the far field regime, the expanding process of fuel air cloud was simulated by using multi phase flow model. The profiles of physical parameters in expanding fuel air cloud were predicted by numerical simulation, and the shape of expanding fuel air cloud computed was in good agreement with the experimental data.

101. Numerical Simulation of the Dispersion of the Fuel Controlled by Igniting Method of the Burster
XIAO Shao qing, BAI Chun hua, WANG Xiao hua, DAI Bi yong, DING Jing
Xiamen Explosion Engineering Corporation, Xiamen 361012, China

Abstract: This paper models the primary split and the motion of the bombshell by means of four methods of the ignition of the burster by ANSYS/DYNA3D. The results demonstrate that methods of ignition of the burster evidently influence the dispersion of the fuel. Thus the methods should be specially taken into account to the study of FAE.

102. Analysis of the Safety and Energy Content of Ammunition Stored in Cases
JIANG Pei xue, REN Ze pei, JIANG Jin yong, CHEN Ming hua, LU Gui e
Department of Thermal Engineering, Tsinghua Universty, Beijing 100084, China

Abstract: The conjugate heat transfer analysis of transient thermal conduction, natural convection and thermal radiation in a case with ammunition, which is a temperature dependent heat sources, was simulated numerically using PHOENICS (Version 1.4). The variation of the maximum temperature and the self ignition hazard in the ammunition was analyzed using both body fitted coordinates and cartesian cordinates. The safety and energy content in the ammunition were analyzed for various storage conditions.

103. Theoretical Calculation of Coherent Anti-stokes Raman Scattering Spectrum
FENG Wei, HE Wei, SHANG Yan bing
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: In the present paper, the computation of simulation method of CARS spectrum is discussed in detail. This method has been used to simulate the nitrogen (N 2) CARS spectra at different temperatures.

104. Study on Ballistic Character of the Low Temperature Sensitivity Charge
SONG Shi yu, WANG Ze shan
Nanjing University of Science and Technologg, Nanjing 210094, China

Abstract: First the paper discussed the process of burning of the low temperature sensitivintyg charge (LTSC) and built the relevant physical model. The second with the help of the burning curve of close bomb, we established the equation of burning gas producing rate of LTSC and the relevant group of interior ballistic equations, and with it we can calculate the imitate result of the mixture charge of LTSC. We find the imitate result almost equal to the actual result of gun.

105. Discussion about Explosive Energy
HU Qing xian
The Institute of Chemical Materials, CAEP. Mianyang 621900, China

Abstract: Explosive energy is evaluated by way of fuzzy mathematics. Sequence is lined up according to explOsive energy and the method of selection of weighted coefficient is discussed.

106. Design and Realization of Liquid Propellant Parameters Module in RLPG Databases
SHAO Jiang dong, YU Yong gang
School of Dynamic Engineering, NUST, Nanjing 210094, China

Abstract: In the paper, the necessity of the building liquid propellant parameters module is analyzed. It also introduces the construction of the module and the realization of its subroutines' function. The module is developed under the Visual FoxPro 3.0. It is very important for the research of the liquid propellant gun.

107. Ignition Models of Explosive Charge Subjected to Setback Impact
ZHOU Pei yi, XU Geng guang, WANG Ting zeng
Beijing Institute of Technology, Beijing 100081, China

Abstract: In this paper the adiabatic compression ignition model and the finte compression rate ignition model subjected to setback impact are summarized and the insufficiencies of these two models are analyzed. The coupled compression ignition model of thermotics and mechanics is advanced. And the Comp B explosive charge's temperature rise subjected to setback impact are caculated by using the thermo elastic plastic model considing the effect of strain rate.

108. Predicting the Detonating Velocity of Explosives by Artificial Neural Network
HUANG Jun, ZHOU Shen fan
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: This paper discussed the quantitative relationship between the detonation velocity and the structure of explosives. Molecular connecting indices(MCIs) are used to represent the structure. Based on the back propagation algorithm, a quantitative model was established after a training process to a train set containing 40 explosives was completed. With the model a forecasting test was made to a predict set of 14 explosives which didn't belong to the train set. The results showed that the yield model reflected the complex relationship between the structure and the detonation velocity, and had high predicting accuracy. This bring forward a novel method for estimating the detonation velocity when designing new explosives.

109. Numerical Simulation for Gas droplet Detonation and a New Method for Continuous boundary
ZHANG Hai bo, BAI Chun hua, DING Jing, HAO Bao tian
Beijing Institute of Technology, Beijing 100081, China

Abstract: With TVD scheme and MacCormack method, also a new artificial compression method and MaxEta method, we investigate the process of gas droplet detonation and shock wave propagation . We also give a new method for continuous boundary, “vertical disturbing method”. Very good results are got.

110. Calculation of Pyrotechnic Composition Equilibrium Products Based on Principle of Free energy Minimization
WANG Xue, PAN Gong pei, LI Yi
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: Calculation of pyrotechnics composition equilibrium products is very important in pyrotechnic field. The broydn method is used in this paper to calculate the equilibrium products of pyrotechnics composition based on the principle of free energy minimization. The calculation results satisfy with the experimental results. The calculation program can be used on imperfect gas with higher precision by extension databases.

111. Structure and Phase Transitions in Nitrocellolose Plasticized with Di and Tri Ethyleneglycol Dinitrate
SHAO Zi qiang, Yu. M. Lotmentsev
D. Mendeleev University of Chemical Technology of Russia

Abstract: Thermodynamic compatibility, mechanism of structure and transitions in the plasticized nitrocellulose system were studied in the artical. Phase diagram of the system within the wider temperature range were presented.

112. A Prediction Method for Brisance and Power of Industrial Explosive
SHI Jun
Zhejiang No.785 Factory, Shengzhou 312400, China

Abstract: Based on the explosive theory by use of the measurement date a relationship beteween brisance and detonation velocity power and detonation velocity and brisamce of industrtal explosive wers set up, also a predication method for brisance and power were proposed.

113. Study of Predicting TNT Red Water’ s Pre treatment Effect with Artificial Neural Network
HUANG Jun, TANG Wan ying, ZHOU Shen fan
College of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: TNT red water is a poisonous effluent which is difficult to biotreat. It is necessary to pretreat properly before its biodegradation. In this paper, a mathematical model between TNT red watet’s pretreatment effect and the conditions is established based on a promoted BP neural network algorithm, and a program is compiled to realize this algorithm. With this model, pretreatment effect values under different conditions are predicted, the results show that this method is effective.

114. The Dipole Moment of Nitrotoluenes
GUO Yan wen
Beijing Institute of Technology, Beijing 100081, China

Abstract: Phenomenological and theoretical interpretation of the dipole moment was discussed in this paper. The diploe moment of nitrotoluene (the series of nitro toluene) are dependent on the geometric structure and was calculated in first approximation from the vectorial summation of the bond dipoles, that can be used for reference of fundamental study of organic chemistry and process analytical chemistry.

115. Discussion on the Establishment of the Database about the Safety of the Powder and the Explosive
HU Yi ting, CHEN Wang hua, PENG Jin hua, LIU Rong hai
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: According to the suggested model which summarizes the hazards of the powder and the explosive, and evaluates the safe property of the production and transportation system of the powder and the explosive, it is considered how to establish a general and practicable database for the evaluation of the powder and explosive . With the discussion of the content、 method of the expression of the data, method of the search of the data and the step of the establishment of the database, the user and the main function of the database are explained.

116. Research on the Combustion Wave Structure of Solid Rocket Propellants
WANG Ning fei, WANG Hong, WANG Liang
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: A numerical calculation method for analyzing combustion wave structure of solid rocket propellants has been designed. Using this method we can get the detail information of chemical reactions in the condensed phase of homogeneous solid propellants. We believe that there would be no condensed gas interface, and the surface temperature would be no meaning. From results of combustion waves of a modified double base propellant, we believe that in solid phase there would be multi stage reaction mechanism, and that the reaction mechanism would be the same in condensed phase at different pressures, only the reaction heat release value would be not same. We also believe that Π thermocouple would be insuitable for measuring combustion wave of nonhomogeous propellants.

117. The Numerical Modeling of Mechanical Response of Energetic Materials to Confined Triaxial Compression
HAN Xiao ping, ZHANG Yuan chong
Northwethern Polytechnical University, Xi'an 710072, China

Abstract: Numerical modeling of friction is conduted under confined triaxial compression. On the basis of the experiment curves a method of computer numerical modeling comtinign these curves is presented to determine some parameter, such as Poisson′s ratio and fricion coffictient etc. Using a commerical FE code, the friction cofficient between the cylindrical surface of the explosive sample and the inner wall of the confining cylinder are evaluated. Having taken into account friction, the amendment of yield strength is done.

118. Numerical Simulation of the Burning Rate Pressure Index of Nitramine Modified Double Based Propellants
YANG Dong, SONG Hong chang, LI Shang wen, CHEN Shu ling
Nanjing University of Science and Technolgy, Nanjing 210094, China

Abstract: In this paper, a chemical mathematic model for the pressure index of nitramine modified double based propellants is presented , and the expression of pressure index is given. The pressure index can be calculated from propellant component by using this expresure. The results show a good agreement with both of the change regularity and the experimental data of pressure index. In the meantime, based on the basic model, the chemical structure factors which influence the pressure index are discussed.

119. Improving the Ballistic Performance of Programmed splitting Stock Propellant by Means of Deterred and Mixed Charge
Huang Hongyong Wang Zeshan
School of Chemical Engineering, NUST, Nanjing 210094

Abstract: By analysing and theoretical calculating, this paper proves that the deterred and mixed charge is an effective way to improve the ballistic performance of programmed splitting stock propellant(PSS). At least two aspects of the performance of PSS charge can be improved: ① It can eliminate the low “V” valley of double peak pressure time curve of PSS charge and form the pressure time curve similar to plateau, even plateau, so the pressure efficiency and muzzle velocity of gun system is raised greatly on the condition of given maxium pressure;② It can reduce the temperature coefficient of PSS charge and make the application of PSS charge in gun more practically.

120. Numerical Computation on the Critical Temperature of Thermal Explosion of NTO Salts
Yang Zhengquan Hu Rongzu
Xi'an Modern Chemistry Research Institute, Xi'an 710065

Abstract: A numerical method for computing the critical temperature (T b) of thermal explosion of energetic materials from a set of data of thermal explosion temperature (T i) and determined explosion induction (t i) is presented. The corresponding program to calculate the value of T b from a set of data of T i, t i (i=1, 2, …, n) is compiled in BASIC language. The difference between the calculated values of T b and literature ones of ethylenediammonium salt (ENTO), lead salt (PbNTO), ammonium salt (ANTO) and potassium salt (KNTO) of 3 nitro 1, 2, 4 triazol 5 one (NTO) is within 6%.

121. Influence of Environmental Conditions on the Temperature Variation and Safety of Ammunition in Storage
Jiang Peixue Ren Zepei Jiang Jinyong Chen Minghua Lu Gui'e
Department of Thermal Engineering, Tsinghua University, Beijing 100084

Abstract: The influence of the environment (boundary conditions) on the self ignition hazard in ammunition is investigated numerically. The analysis shows that the environmental temperature and the heat transfer between the container surface and the surroundings influence the temperature variation and safety. Therefore, efficient cooling heat transfer around the ammunition must be maintained to avoid self ignition.

122. A New Method for Predicting Explosive Performance in the Cylinder Test
Wang Keqiang
Department of Chemistry, East China University of Science and Technology, Shanghai 200237

Abstract: Based on the molecular structure, a new method was developed which can be used to predict the wall velocity of cylinder test by the composition of the explosive. The calculated results showed that the predicted values of wall velocity were in good agreement with the experimental data and had an advantages over the existing methods.

123. Impact Sensitivity and Intramolecular Hydrogen Bond in Sustituted Nitrobenzenes
Zhang Dechun Zhang Yanqiu
Department of Chemistry, Suzhou University 215006

Abstract: The relations between impact sensitivity and various molecular properties in 30 substituted nitrobenzenes were studied using AM1 method. It is found that the bond length of the trigger bond in the molecule is linearly correlated with the h50 very well. The hydroxynitrobenzenes are completely different from the others in this respect, suggesting the trigger bond in these molecules is the O-H bond in contrast to the C-NO 2 bond in the others. The differency is originated from their different resonance assisted intramolecular hydrogen bonds.

124. The Assessment of Pressure Temperature Coefficient of Solid Rocket Propellants
Chen Qiang Hou Genxiang Duan Anping
Xian Modern Chemistry Research Institute, Xian 710065

Abstract: The problems in present assessment of the pressure temperature coefficient were pointed out, the variation law of the pressure temperature coefficient was systemically analyzed, and the method in calculating standard pressure coefficient was also established.

125. The Application of CAD Technique to the Potential Titrimetric Analysis about Composition of Liquid Propellants
Jiang Shujun Yu Bin
Xian Modern Chemistry Research Institute, Xian 710065

Abstract: This paper summarizes the CAD practice in the composition analysis of liquid propellants. It is related to the disign of interface circuit between transient converter and potential titrimetry, and the techniques about digitized measuring and computer programming of data processing .

126. Research the Density of PBX Using Aritificial Neural Network
Li Jianfeng Wang Leina * Chen nianyi
Shanghai Institute of Metallurgy 200050; *Xi'an Modern Chemistry Research Institute 710065

Abstract: The densities of a kind of Polymer Bonded Explosive(PBX) which were calculated using artificial neural network(ANN) and density equation for mixture have been compared. The results indicated that ANN can show the correct relationship between composition, temperature and density of the PBX. The prediction model created by ANN also can be used correctly to predict the densities of unknown samples.

127. Quantum Chemical Study On The Impact Sensitivity of Polynitroaromatics
Li Jinshan Zeng Gang
Institute of Chemical Materials, CAEP, Chengdu 610003

Abstract: In this paper, by using PM3 method, the geometry is optimized and the electronic structure in equilibrium geometry is calculated for polynitroaromatic series. The calculated results show that the Mulliken bond order of C—NO 2 trigger linkage is in good agreement with the observed 50 , and the—N(CH 3)(NO 2)group is activated when two NH 2 groups are added to Tetryl.

128. Calculation Study in Steady Combustion Properties of AP CMDB Propellants
Zhang Wei Zhu Hui Wang Qiyan
National University of Defense Technology, Changsha 410073

Abstract: In this paper , a steady combustion model of AP CMDB propellant, which can be used in the combustion property calculation of AP CMDB propellants as well as classic DB Propellants, was developed. The values calculated with the model are in accordance with the burning rates from references. The calculated results show that the burning rates of the AP CMDB propellants increase with the decrease in the particle size of AP and with the greater content of AP. On the other hand , the higher the energy of the binder system, such as an increase in the content of NG or in the nitrification degree of NC, the greater the burning rates of the propellant.

129. Molecular Dynamics Simulation on Compatible Evaluation of HTPB and Plasticizers Blends
Lan Yan-hua, Liu Ya-qing and Fu Yi-zheng, Chinese Journal of Energetic Materials, 2010, 18(1):42~46

Abstract: The density, binding energy and radical distribution function of HTPB/plasticizers blends and binder hydroxyl-terminated polybutadiene (HTPB), and plasticizer dioctyl sebacate (DOS), dioctyl adipate (DOA), dibutyl phthalate (DBP), dioctylphthalate (DOP) were calculated by molecular dynamics simulation (MD) for evaluating compatibility of HTPB and plasticizers. The results show that Δδ value of pure substance, the density added value, binding energy and radical distribution function value, the compatibility of HTPB and plasticizers can be obtained, and the order of compatibility are as follows: HTPB/DOS>HTPB/DOA>HTPB/DOP>HTPB/DBP.

130. Numerical Simulation and Burning Rate of B/CuO Delay Compositions
Chen Yi, Hui Yun-long, Li Yan-chun and Yan Shi, Chinese Journal of Energetic Materials, 2010, 18(1):68~71

Abstract: The law of the burning rates of B/CuO delay compositions at ambient temperature from -50 ℃ to 70 ℃, and with the boron contents increasing from 8.3% to 20% were studied. Results show that when the boron content is 8.3%, the B/CuO delay compositions are misfired, and the burning rates increase with increasing of boron contents from 11% to 20%. When the boron contents are from 14% to 18%, the burning rates almost keep the same value. With the increasing of ambient temperature, the burning rate also has a little increase. Least square method was used to simulate the burning rates, and a burning rate formulation of B/CuO delay compositions was put forward.

131. Numerical Simulation of High Explosive Detonation Process Using SPH Method with Fully Variable Smoothing Lengths
QIANG Hong-fu, WANG Kun-peng, GAO Wei-ran , . Chinese Journal of Energetic Materials, 2009, 17(1):27~31

Abstract: The numerical simulation of the detonation of a high explosive (HE) is difficult for traditional grid based methods due to the mesh distortion. Smoothed particle hydrodynamics (SPH) method, as a Lagrangian particle method, is a best candidate method to solve this kind of problem. Modified SPH method presented by the authors with fully variable smoothing length corrects the variable smoothing length effects of standard SPH method in essence, and improves the simulation precision and stability in the large density gradient problem. 1D TNT slab detonation and 3D TNT shaped charge were simulated with the new method and compared with the standard SPH method and theoretical value. The results show that the new SPH method improves the precision and computes the CJ value more correctly. With the numerical simulation for detonation process of the 3D TNT shaped charge, the properties and the rule of the gaseous detonation products were obtained. The results accord with the explosion theoretical value.

132. Thermodynamics Calculations of Diatomic Molecules Based on Morse Potential
XU Yang-sen, LU Zhuan , WANG Ming-liang , TIAN De-yu , LIU Jian-hong , Chinese Journal of Energetic Materials, 2009, 17(1):32~35, 41

Abstract: The thermodynamic properties for some metal-containing(Cu, Fe, Pb, Cr, Sn, Ge) diatomic molecules were studied by density functional theory (DFT) method at B3LYP/6-311G(d, p) and B3LYP/SDD levels and statistical mechanical method based on Morse potential in 300K-5000K. Results show that the heat capacity and entropy obtained CuO, CuCl, FeO and CrO diatomic molecules are in a good agreement with reference data with the deviation of no more than 0.7(JK-1mol-1), and the entropy variations for GeX, SnX and PbX (X= S, Se, Te) are less than 0.75% in comparison with the reference data.

133. Molecular Dynamics Simulation of Plasticizer Diffusion
LI Hong-xia, QIANG Hong-fu, WANG Guang and WU Wen-ming, Chinese Journal of Energetic Materials, 2009, 17(1):36~41

Abstract: To overcome the disadvantage of experimental methods, plasticizer diffusion in the bond system of hydroxyl terminated polybutadiene (HTPB) propellant was simulated by the molecular dynamics (MD) method. The molecular models of plasticizer and the bond system were constructed in the software of Materials Studio 4.3. The mixture system performed geometry optimization was simulated under the condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) force field. The mean square displaces of plasticizer in the bond system were obtained by statistical average. The plasticizer diffusion was obtained by Einstein equation. The diffusion coefficients (10-4cm2s-1) of dioctyl sebacate (DOS) are respectively 0.0010, 0.0020, 0.0025, 0.0031, 0.0043 at the temperature of 273, 298, 310, 323, 348 K; and are respectively 0.0025, 0.0020, 0.0018, 0.0015 at the content of 23%, 37.5%, 47%, 60%. The results show that the diffusion coefficients gradually increase with increasing of environmental temperature and decrease a little with increasing of the DOS content.

134. Numerical Simulation of Cook-off for Explosive at Different Heating Rates
WANG Pei, CHEN Lang and FENG Chang-gen, Chinese Journal of Energetic Materials, 2009, 17(1):46~49, 54,

Abstract: A cook-off model of explosive was established to investigate the characteristics of explosive thermal reaction at different heating rates. The numerical simulation was employed to model the cook-off process for GHL explosive at different heating rates by computational fluid dynamics(CFD) software. The decomposition reaction of explosive was described by Arrhenius-equation. According to T-t curves of cook-off test at heating rate of 1 Kmin-1, the activation energy and frequency factor were confirmed. The calculations were conducted to simulate the cook-off tests for GHL explosive at heating rates of 3.3 Kh-1, 1 Kmin-1, 3 Kmin-1 and 10 Kmin-1, respectively. The results show that the external heating rate has much influence on the ignition time and ignition location. The ignition time of explosive decreases and ignition location removes from the interior to the edge of explosive cylinder with increasing of the heating rate. The ignition temperature is slightly affected by the heating rate. The environment temperature at igniting in slow cook-off test is lower than that in fast cook-off test.

135. Numerical Simulation of Stress Distribution and Analysis of Damage Trend of NEPE Propellants
CHEN Yu, LIU Yun-fei, XIA Ji-dong and TAN Hui-min, Chinese Journal of Energetic Materials, 2009, 17(1):87~90

Abstract: According to the composition and structure properties of the NEPE propellants, the finite element calculation model of the NEPE solid propellants was established by the ANSYS 10.0 finite element calculation software. The damage trend and variation regularity of the NEPE propellants under unilateral tensile was simulated. Effects of the solid particle content, bonding agent content, composition and particle diameter of the oxidant on the damage trend of NEPE propellants were discussed by comparing the stress concentration factor α and the debond angle θ. The results show that the mechanical performance simulated by the established finite element model of the NEPE solid propellants is in good agreement with the experimental regularity.

136. Progress in Predicting the Effective Elastic Properties of PBX
JING Shi-ming, LI Ming and LONG Xin-ping, Chinese Journal of Energetic Materials, 2009, 17(1):119~123

Abstract: Polymer bonded explosives are particulate composites containing elastic particles in a viscoelastic binder. The particles occupy an extremely high fraction of the volume, often greater than 85%. Under low strain rate loading and at about room temperature, the elastic modulus of the particles can be four order of magnitude higher than that of the binder. These two characteristics make effective elastic properties predict more difficultly. As a result, PBXs provide unique challenges for micromechanical modeling. Some micromechanical-based methods for the determination of mechanical properties of PBX were introduced, the advantages/disadvantages and the prospects of these methods were reviewed briefly. Three-dimensional models with damage, using computed tomography images and simulating manufacturing process are suggested to be the key point of future work

137. Numerical Analysis of Factors Affecting Flow Property of Gel Propellants in Round Pipes
QIANG Hong-fu and XIA Xue-li, Chinese Journal of Energetic Materials, 2009, 17(2):137~142

Abstract: To evaluate the effect of the tapered round pipe geometry, volumetric flow rate and gellant type or content on the pressure drop, the velocity and viscosity fields, the governing equations of the steady, incompressible, isothermal, laminar flow of a Power-Law, shear-thinning gel propellants in pipe were formulated, discretized and solved. A SIMPLEC numerical algorithm was applied for the solution of the flow field. Results show that the mean apparent viscosity decreases with increasing of the volumetric flow rate and increasing of the gellant content results in an increase in the viscosity. The results also show that the cone semi-angle can produce additional decrease in the mean apparent viscosity of the fluid. The mean apparent viscosity decreases significantly with increasing of the convergence angle of the pipe, and its value is limited by the Newtonian viscosityη∞. The effect of the cone semi-angle on the mean apparent viscosity is more significant than that of the volumetric flow rate and the gellant type or content on the mean apparent viscosity. Additional decreasing of the viscosity results in an increase in the pressure drop with the increasing of cone semi-angle. It is important to pipe design that the viscosity decreasing and the pressure drop increasing are taken into account together.

138. Numerical Simulation of Effect of Different Initiation Positions on a Certain Focusing Fragment
YAN Han-xin, JIANG Chun-lan, LI Ming and WANG Zai-cheng, Chinese Journal of Energetic Materials, 2009, 17(2):143~146

Abstract: To increase fragment warhead performance, aimable fragment warheads were widely designed and developed to obtain high lethality against air target. A certain focusing fragment warhead driven by two different places of detonation respectively, were numerically simulated by using DYNA3D. To obtain the fragment distribution density, target was modeled numerically at 6 m far away from the fragment warhead. The simulation results show that the fragments can focus on the target, and the fragment ejection angle and azimuth angle agree with each other. The velocity of directional fragment under two asymmetric points initiation is 20.3% faster than that under the center initiation, and the fragment distribution density under two asymmetric points initiation is 9.6% greater than that under the center initiation. Simulation results could be used for the initiation system of focusing fragment warhead in engineering practice.

139. Simulation of Neyer D-Optimal Senstivity Test
ZHOU Li-dong, WEN Yu-quan, WANG Pei-lan and WANG Jun-bo, Chinese Journal of Energetic Materials, 2009, 17(2):152~156

Abstract: In order to study the characteristics and the influence factors of the parameter estimation of Neyer D-optimal sensitivity test, the effects of the initial guesses of parameters and the sample size on the precision of parameter estimation were studied by computer simulation. Results show that the mean estimation is unbiased; about one-third of the standard deviation estimation is smaller and two-thirds of the standard deviation estimation is bigger; the initial guesses of the parameters have a little effect on the precision of parametric estimation; a better mean estimation can be obtained if sample size is more than 18.

140. Experimental Study on Tensile Damage Process of NEPE Propellant
LI Jing-ming, ZHENG Xue, LI Wei and ZHAO Xiao-bin, Chinese Journal of Energetic Materials, 2009, 17(2):241~243

Abstract: In order to study the damage process of NEPE propellant during tensile condition, the micro-structure of NEPE sample was observed by in situ SEM. The results show that the interphase dewetting and crack are first founded around big grains. And the binder is pulled into silk shape. Then the crack in NEPE propellant extends through the big grains and collects into macro-crack. On the other hand, the stress distribution in grain-binder unit was also analyzed by finite element method. The analysis shows that the effective stress in big grain-binder unit is much greater than that of small grain-binder unit. So, the main damage model of NEPE propellant during tensile process is interphase damage between big grain and binder.

141. The Estimation of Characteristic Drop Heights of Impact Sensitivity for Polymer Bonded Explosives JH-94 and JO-96
HU Rong-zu, ZHAO Feng-qi, GAO Hong-xu, ZHANG Hai, ZHAO Hong-an, WANG Xi-jun, ZHANG Xian-liang, FENG Yu and MA Hai-xia, Chinese Journal of Energetic Materials, 2009, 17(3):251~254

Abstract: Friedman′s formula for calculating the characteristic drop height of impact sensitivity (H50) of energetic materials(EMs) was derived. A numerical method of estimating the value of H50 was presented. The corresponding computer program was written. The experimental 50% drop height of eight EMs: HMX，RDX，TNT，PETN，BTF，BTF，Tetryl，NG were certificated with the programmed program，considering that the programmed program is suitable for fast computation of H50 and predicted 50% drop heights for PBX-JH-94 and PBX-JO-96 are believable to a certain extent

142. Study on the Isomers and Crystal of Carbohydrazide by Density Functional Theory
HUANG Hui-sheng, ZHANG Jian-guo, ZHANG Tong-lai and WANG Li-qiong, Chinese Journal of Energetic Materials, 2009, 17(3):255~259

Abstract: The gaseous isomers and crystalline state of carbohydrazide (CHZ) were studied at the DFT-B3LYP/6-31G** level. Three stable isomers were located. The structure Ⅱ，which is in agreement with the structure in the crystal，is the most stable. The vibrational frequencies were analyzed and they agree well with the experimental results. The terminal nitrogen atom of the hydrazine group and oxygen atom of the carbonyl group are preferable coordination sites for CHZ molecule and this was demonstrated by the experimental results. The intermolecular interaction is strong in the crystal. Furthermore，all of the atoms have contributions to the frontier bands. Some bands are very oscillatory，which show that the corresponding molecular orbitals are strongly perturbed by the crystalline environment.

143. Structure-properties of Diethylmetallic Azides Clusters of Aluminum and Gallium by DFT
XIA Qi-ying, MA Deng-xue and YANG Ji-min, Chinese Journal of Energetic Materials, 2009, 17(3):260~264

Abstract: (Et2MN3)n (n=1 to 3，M=Al，Ga) clusters were studied by DFT/B3LYP method with SDD basis set. The dimer(Et2MN3) 2 and trimer(Et2MN3)3 (M=Al，Ga) are found to exhibit four-membered M2N2 and six-membered M3N3 ring structure，respectively. Compared with the monomer，the order of the bond length changes for the dimer(Et2MN3) 2 and trimer (Et2MN3)3 (M=Al，Ga) is as follows: Nα—M>Nα—Nβ>Nβ—Nγ≈M—C. Binding energies of the dimer (Et2AlN3) 2 and trimer(Et2AlN3)3 clusters are 35.44 and 45.61 kJmol-1 lower than that of (Et2GaN3) 2and(Et2GaN3)3 clusters，respectively. Thermodynamic properties show that the dimer is the main composition of the(Et2MN3)n (n=1 to 3，M=Al，Ga) clusters at 298.2 K. The dimerization and trimerization are very favorable thermodynamically below 500 K.

144. Estimation and Its Applicability of D-Optimality-Based Sensitivity Test under Different Prior Information
FU Dong-xiao, ZHANG Rui, LI Fang, XIE Gao-di and XU Feng-yi, Chinese Journal of Energetic Materials, 2009, 17(3):339~343

Abstract: The effects of different prior (known) information on the estimation precision of mean and standard deviation value from D-optimality-based sensitivity test method were studied by Monte Carlo simulation，and the results were compared with that from the other two sensitivity test methods(up-and-down method and Langlie method). The results show that the primary test parameter has less effect on the estimation precision from D-optimality than that from the other two methods. More accurate mean values can be obtained when enough prior information is available，while better standard deviations can be obtained from D-optimality method. In the case of deficient prior information，the value mean is more precise from D-optimality method than that from the other two methods. When mean is known and standard deviation is unknown，more accurate estimation of mean can be obtained by Langlie method，while more reliable standard deviation can be obtained from D-optimality method. Generally，better estimation of standard deviation and P respond value are obtained by D-optimality than that by the other two methods in any case.

145. Numerical Simulation of Array Heat Transfer of Chemical Microthruster
LIU Jian, YE Ying-hua, SHEN Rui-qi and HU Yan, Chinese Journal of Energetic Materials, 2009, 17(3):357~360

Abstract: Based on the mechanism of heat transfer，a one-dimensional finite difference model describing combustion process and array heat transfer of chemical microthruster was established. With this model，the temperature growth process and temperature distribution of unit wall of epoxy resin，7740# glass，microcrystal glass and silicon units filled with lead styphnate were obtained by numerical simulation. Results show that heat conductivity and combustion time of microthruster unit are the main factors affecting growth of temperature and integration level. Larger heat conductivity and longer combustion time lead to less microthruster unit on a same area. When heat conductivity increases by 100-1000 times，critical distance increases by 3.3-3.6 times，and when combusion time increases by 1 time，critical distance increases by 3-5 times. And critical distance is limited only in micron-size: silicon unit is 150-450 μm，and the other three types are 20-160 μm.

146. Elman Model in Prediction of COD Removal Rate of Booster Explosive Wastewater
LIU Yu-cun, YU Guo-qiang, WANG Shao-hua and CHANG Shuang-jun, Chinese Journal of Energetic Materials, 2009, 17(3):361~364

Abstract: In order to predict the chemical oxygen demand(COD) removal rate of the diazodinitrophenol(DDNP) wastewater treated by supercritical water oxidation(SCWO)，the HXDK-01-A intermittence type supercritical water oxidation device was used to dispose the actual industrial production wastewater，and the effects of reaction temperature，reaction pressure，residence time，oxygen excess on COD removal rate were studied. A single hidden layer Elman prediction model was established by using the reaction temperature，reaction pressure，residence time，oxygen excess as input variables，and using the COD removal rate as output. The MSE of the Elman model is 0.0418，the biggest error is -0.3231，and the least error is 0.0296，the MSE of the multiple regression is 0.3149，the biggest error is 0.8830，and the least error is 0.2200. The Elman neural network prediction results are better than that of multiple regression analysis. Results show that the Elman model can be adopted to predict the COD removal rate of the wastewater treated by SCWO.

147. Numerical Simulation and Experimental Validation of RHT Solidification Process
LI Jing-ming, TIAN Yong, ZHANG Ming, GUO Peng-lin and ZHANG Wei-bin, Chinese Journal of Energetic Materials, 2009, 17(4):428~430

Abstract: In order to understand the solidification process of casting explosive, the temperature fields of RHT explosive during solidification process were simulated by finite element method. The shrinkage of RHT explosive after solidification was also predicted. The results show that the temperature difference between inner and outer of RHT explosive during solidification process is quite great. There exists an inflexion on the temperature curves in the centre area. And the porosity will be presented on the middle position of solidified RHT explosive. On the other hand, the temperature of RHT explosive during solidification process was also tested by thermocouple and the interior quality was inspected by ICT, and the simulated results and tested results were also compared. The results show that the finite element method can be used to simulate the RHT explosive solidification process

148. Theoretical Studies on Intermolecular Interactions between Azacalix［6］arene and HMX
ZHANG Wen-yan, CAO Duan-lin, HOU Su-qing, WANG Jing, SHI Yong-wen, LI Ke-san, LIU Mei-feng and GU Yong-long, Chinese Journal of Energetic Materials, 2009, 17(4):436~441

Abstract: Four optimized structures of azacalix［6］arene host monomers (Ma-M d ) and their complexes (a-d) with HMX were obtained at B3LYP/6-31G(d) level. Natural bond orbital (NBO) analysis was performed to reveal the origin of the interaction between hosts and objects. The intermolecular interaction energy was evaluated with basis set superposition error correction (BSSE) and zero point energy correction (ZPEC). The B3LYP/6-31G (d) calculations on the four complexes show that the largest interaction energy is -13.98 kJmol-1 in the complex composed of HMX and hexaazacalix［3］-p-triarene［3］-2-amido-1, 3, 5-triazine. Results show that intermolecular interaction energies of azacalix［6］arenes with substituted groups are stronger than that without substituted groups, and intermolecular interaction energies of azacalix［6］arenes with amido groups are stronger than that with nitryl groups.

149. Study on Tera-hertz Spectroscopy of HNS
HUANG Ping, SHI Wei-fan, ZHANG Cun-lin, QIAN Xin-ming and LIU Zhen-yi, . Chinese Journal of Energetic Materials, 2009, 17(5):544~548

Abstract: The absorption spectra of HNS, in the frequency range of 0.2-4.0 THz, were calculated by using quantum chemistry calculation method, and the theoretical calculation results show that the characteristic peaks of HNS are located in 1.9 THz and 3.3 THz. The experimental results offered by THz time-domain spectroscopy technology and FTIR show that the characteristic peaks of HNS are located in 1.7 THz and 3.1 THz. The experimental results agree with the theoretical calculation results, which show that HNS has distinct characteristic absorption peaks in the frequency range of 0.2-4.0 THz.

150. Molecular Dynamics Simulation of Isotherm and Elastic Properties of HMX
SHI Yi-ding and HUANG Feng-lei, Chinese Journal of Energetic Materials, 2009, 17(5):561~567

Abstract: The isotherms and elastic properties of β -HMX crystals were calculated through molecular simulations in NPT ensemble using COMPASS force field. The isotherms of β -HMX simulated were in reasonable agreement with experiments. The pressure-induced changes of the lattice parameters showed the anisotropic compression of β -HMX. The bulk modulus K0 and its pressure derivative K0′ were obtained by fitting the isotherms to different equations of state. However, the values of K0 and K0′ obtained from the isotherm are sensitive to the fitting forms of equations of state. The elastic constants and modulus were calculated by statistic analysis mode at different pressures in the range of 0~27 GPa. Cauchy pressure C12-C44 and G/K ratios were also calculated which indicated that β -HMX would become harder as the pressure increased, and as well the β -HMX elastic property transformed from brittleness to ductibility.

151. Numerical Simulation of Cook-off about Phase Transition of Explosive
CHEN Lang, WANG Pei and FENG Chang-gen, Chinese Journal of Energetic Materials, 2009, 17(5):568~573

Abstract: Burning or detonation reaction occurs after phase transition during cook-off for of low-melting point solid explosives. A thermal reaction model of explosive was established according to TNT cook-off test. Besides heat conduction, self-decomposing reaction, the phase transition and heat convection of liquid explosive were considered. The calculation was conducted to model the TNT cook-off by CFD software (Fluent). The ignition time (4150 s) and ignition temperature (226 ℃) are achieved. Comparing the calculated results with the measured, the calculation model and relevant parameters of TNT were validated. The phase transition and temperature distribution in explosive were respectively analyzed at 0.3 Ks-1, 0.05 Ks-1 and 3.3 Kh-1 heating rate. Results show that phase transition occurs from the surface to the exterior of explosive. The unmelted explosive sinks in melted explosive because of the pull of gravity. The heat energy is needed for melting explosive. So the explosive temperature rises slowly. After all explosives have been melted, the temperature rises rapidly due to the convection. There is a little difference in temperature of liquid TNT because of heat conduction and convection. The ignition temperature, ignition time and ignition position of explosive are affected by phase transition of explosive.

152. Effect of L-J or Exp-6 Potential Function on Calculation of Reduced Second Viral Coefficient
HAN Yong, LONG Xin-ping, HUANG Yi-min and JIANG Zhi-hai, Chinese Journal of Energetic Materials, 2009, 17(5):574~577

Abstract: In order to study the effect of potential function (L-J, Exp-6) on calculation of the reduced second Viral coefficient B*(T*), the Simpson′s changing step length integral was introduced to approximately calculate the different B*(T*). The calculation results are in agreement with literature values, which prove the availability of the calculation method introduced. By the comparison of B*(T*) L-J calculated by L-J potential function and B*(T*) Exp-6 calculated by Exp-6 potential function, the changing relationship between difference value(Δ(T*)) and reduced temperature(T*) was obtained. The result reveals that in detonation environment, when T* is 25-40, there is obvious difference between B*(T*) L-J and B*(T*) Exp-6.

153. Application of Integral Isoconversional Non-Linear Method in Thermal Analysis of Explosives
GAO Da-yuan, SHEN Chun-ying, HE Song-wei and ZHOU Jian-hua, Chinese Journal of Energetic Materials, 2009, 17(5):578~582

Abstract: The mathematics expression of apparent activation energy of thermal decomposition reaction calculated from integral isoconversional non-linear (NL-INT) method was derived from the evaluation function when decomposition extent α was the same value from non-isothermal decomposition kinetic equation. The thermal decomposition apparent activation energy of HMX, HMX based PBX, TATB, PETN explosives and F2314, SD-33 bonders were calculated by NL-INT method based on the TG curves at heating rates of 5, 10 and 20 Kmin-1, respectively, and the results calculated by NL-INT method and Ozawa′s method were analyzed and discussed. Results show that the method can conquer errors caused by approximation of temperature integral and choice of mechanism function, and the apparent activation energy obtained were more nicety.

154. Numerical Simulation of Explosive Machining
ZHANG Qiu and HUANG Jiao-hu, Chinese Journal of Energetic Materials, 2009, 17(5):583~587

Abstract: Numerical simulation and related models for HMX based PBX explosive machining were performed and studied by using LS-DYNA. Tool forces with various cutting parameters were computed for HMX based PBX explosive, and the calculational results agree well with the experimental results. Results show that the plane strain model is reliable for simulation of explosive machining when cutting width is far greater than cutting layer thickness. Effective stress failure criterion is appropriate for simulating chip separation of explosive. The tool force increases with increasing of depth of cut and feed rate, and cutting speed has no obvious effect on tool force. Depth of cut affects tool force most greatly among the three parameters.

155. Molecular Simulation on Mechanism of Bonding Agents in HTPB Solid Propellant Model
JIAO Dong-ming, YANG Yue-cheng, QIANG Hong-fu and WU Wen-ming, Chinese Journal of Energetic Materials, 2009, 17(6):650~654

Abstract: In order to explore the effect of bonding agents on the mechanical properties and chemical ageing resistance of hydroxyl-terminated polybutadiene (HTPB) solid propellant, molecular dynamics method and COMPASS force field were adopted to simulate the adsorption energy and mechanical properties of the interfaces constructed by HTPB, bonding agents and crystal faces of Al and Al/Al2O3. Then simulations were applied to estimate the diffusion coefficients of H2O and O2 in different bonding agents membranes. The results show that bonding agents increases the interaction of solid grain and HTPB, and improves elastic modul of Al/HTPB layer showing the enhancement of HTPB system rigidity. The trend of ability of restraining the diffusion of gas is consistent with experimental chemical ageing resistance of different bonding agents.

156. Heat Loss Correction in Closed Bomb Tests
ZHAO Jun, LIAO Xin and WANG Ze-shan, Chinese Journal of Energetic Materials, 2009, 17(6):726~730

Abstract: Based on the fast change of pressure in closed bomb tests, a heat flux equation focused on pressure factor was deducted. A one-dimensional semi-infinite model of calculating inwall heat transfer in closed bomb tests was established and the expression of heat transfer was obtained. The model was validated by double base aromatic-3 (SF-3), TEGDN (TG) propellant and triple-base propellant. The results show that the error between corrected whole heat loss and theoretical whole heat loss is less than 10%,and the burning rate pressure index of SF-3 propellant obtained is close to the expected value.

157. Review on Multifunctional Energetic Structural Materials
ZHANG Xian-feng and ZHAO Xiao-ning, Chinese Journal of Energetic Materials,2009,17(6):731~739

Abstract: Multifunctional Energetic Structural Material (MESM) is a new type of functional material with comprehensive utilization of chemical and kinetic energy. The development of MESM and its application were introduced. The experimental techniques of MESM under shock load, reaction mechanism, and theoretical model were reviewed. The application of shock-induced chemical reactions (SICR) model and empirical molecular dynamic methods which were use to describe the reaction process of MESM were introduced. The current application and the prospects of MESM were reviewed.

158. Synthesis and Quantum Chemical Study on 2,6,8,12-Tetranitro-2,4,6,8,10,12-hexaazaisowurtzitane
LI Yu-chuan,QI Cai,SUN Cheng-hui,PANG Si-ping1 and ZHAO Xin-qi, Chinese Journal of Energetic Materials,2010,18(2):121~127

Abstract: 2,6,8,12-Tetranitro-2,4,6,8,10,12-hexaazaisowurtzitane (TNH2IW) was synthesized from 2,6,8,12-tetraacetyl-2,4,6,8,10,12-hexaazaisowurtzitane (TAIW) by protection, nitration and deprotection. TNH2IW could also been obtained by reduction of hexanitrohexaazaisowurtzitane (HNIW, CL-20) with SnCl2. The molecular geometries, electric structures, and thermodynamic properties of TNH2IW were calculated using the density functional theory (DFT) method at the B3LYP/6-31G* level. The thermodynamic parameters including heat capacities and entropies were calculated, and also the polynomial functions between thermodynamic parameters and temperature were determined. The accurate heat of formation 461 kJmol-1 of TNH2IW in gas phase was obtained via designed isodesmic reaction in which the cage and the nitro group have been kept. The data obtained from the present study show a satisfactory detonation performance, with detonation velocity of 9.13 kms-1 and detonation pressure of 38.9 GPa, both of which are higher than those of TNT and RDX, not worse than those of HMX counterparts.

159. Prediction of Enthalpy of Formation of Aromatic Polynitro Compounds by Bond Parameter Method
TIAN De-yu,WANG Xiao-xuan,LIU Jian-hong,HONG Wei-liang and HUANG Gui-sen, Chinese Journal of Energetic Materials,2010,18(2):128~134

Abstract: Via the molecular structure analysis of aromatic polynitro compounds, bonds in the molecules were coded by bond parameter method and fitted with mathematics method. The obtained regression model was tested and corresponded to the statistics rules. The results of multiple linear regression show a good correlation between the enthalpy of formation and the bond parameters. Correlation coefficient R=0.994, determination coefficient R2=0.988. And the relative error between the predicted values and literature ones of the enthalpy of aromatic polynitro compounds is mostly within ±10%.

160. Experimental and Numerical Calculation Study on Shock Sensitivity of Aluminum Explosive
ZENG Dai-peng,TAN Duo-wang,LI Shang-bin and LI Tao, Chinese Journal of Energetic Materials,2010,18(2):148~151

Abstract: In order to compare and analyze the shock wave sensitivity of a new aluminum explosive, the initiation behavior of two aluminum explosives (HL-10-L-1 and HL-109-L-1) under long period and low value impulse loading were studied using big gap test and numerical calculation. The critical gap thickness and ∫p2dt of nondetonation and nonviolence reaction were obtained. Analysis shows that adopting ∫p2dt value to infer the reaction behavior of explosive under low value pressure pulse is more reasonable than the critical gap thickness

161. Numerical Simulation of Interior Flow Field in a Base Bleed Unit During Working
ZHANG Ling-ke,ZHOU Yan-huang,LU Xin and LU Chun-yi, Chinese Journal of Energetic Materials,2010,18(2):217~221

Abstract: A one-dimensional unsteady flow calculation model of a base bleed unit interior ballistics was established based on the theory of homogeneous flow and solid rocket engine. The inner flow field of base bleed unit and exterior trajectory of a base bleed projectile were simulated via calculating interior and exterior equations of base bleed projectile. The distributions of pressure, temperature, density and velocity of gas and their changing laws at nozzle were investigated and obtained. The calculational results show that the highest temperature and velocity of the gas are 1944 K and 65 ms-1. The working time of base bleed unit is 24 s and increasing range rate is about 30%. Both of working time and increasing range rate are in good agreement with the results obtained from practical shooting tests.

162. Progress in the Constitutive Models Including Damage of Energetic Materials
LI Jun-ling,LU Fang-yun,ZHAO Peng-duo and CHEN Rong, Chinese Journal of Energetic Materials,2010,18(2):229~235

Abstract: The studies and developments in science community of energetic materials with damage mechanics were introduced from two aspects, which are the macro-mechanics phenomenon and the micro-statistic mechanics. The description viewpoints and application ranges of each model were compared and analyzed. It′s necessary to upbuild the multi-scale analysis model, and systematically investigate the damage evolution under different loading modes to establish more reasonable constitutive model of energetic materials.

163. Density Functional Theory Study on Tautomerization of Polyazido-azine
LI Yu-fang,LIAO Xin,JU Xue-hai,YI Jian-hua and XU Si-yu, Chinese Journal of Energetic Materials,2010,18(3):241~246

Abstract: The tautomerizations of polyazido-azine(ring-closure reaction) for 3,6-diazido-1,2,4,5-tetrazine(DiAT) and 2,4,6-triazido-1,3,5-triazine(TAT) were investigated by density functional theory. All of the stationary points(reactants,transition states and products) on the reaction paths were optimized at the B3LYP/6-311G** level. The total energies were obtained after zero-point vibrational energy correction. Enthalpies of formation were derived via the designed isodesmic reactions. The changes of energies,geometries and enthalpies of formation in the tautomerization were analyzed. The cyclization of 3,6-diazido-1,2,4,5-tetrazine processes by two steps with energy barriers of 100.5 and 117.4 kJmol-1,respectively,and the cyclization of 2,4,6-triazido-1,3,5-triazine by three steps with energy barriers of 101.8,99.7 and 108.7 kJmol-1. The enthalpies of formation increase in the process of cyclizations. The ring-closure reaction of TAT is thermodynamically more unfavorable in comparison to that of DiAT. The solvent effect of dimethyl sulfoxide on the tautomerization was evaluated with the self-consistent reaction field (SCRF) method.

164. Theoretical Study on Structure and Properties of N-Methyl-N'-methoxydiazene-N-oxide
XIONG Ying,SHU Yuan-jie,YIN Ming,LONG Xin-ping,ZUO Yu-fen and WANG Xin-feng, Chinese Journal of Energetic Materials,2010,18(3):247~251

Abstract: The structure,enthalpy of formation,density and thermal decompostion mechanism of N-methyl-N'-methoxydiazene-N-oxide(MMDO) were studied based on density fuctional theory,and compared with its nitramino-isomer dimethylnitramine(DMNA). Results show that Z-conformation of MMDO is more stable than that of E-conformation,and Z-conformation of MMDO is the main existence form. The energy barriers of isomerizations between Z and E forms are higher than that of thermal decomposition,accordingly the isomerizations do not occur in the conditions of thermal decomposition. The enthalpy of formation (42.50 kJmol-1) and thermal stablily of Z-MMDO are higher than that of its nitramino-isomer DMNA(-12.74 kJmol-1). However the density(1.331 gcm-3) of Z-MMDO is slightly lower than that of DMNA(1.363 gcm-3). CH3O—N and CH3—O dissociations are two competitive thermal decomposition ways of MMDO.

165. Theoretical Study on Structures and Detonation Performances for Nitro Derivatives of Pyrazole by Density Functional Theory
YI Jian-hong,HU Shuang-qi,LIU Sheng-nan,CAO Duan-lin and REN Jun, Chinese Journal of Energetic Materials,2010,18(3):252~256

Abstract: Twenty-four nitropyzarole compounds and their derivatives were investigated by density functional theory. Their optimized geometries and electronic structures were calculated at the B3LYP/6-311G(d,p) level. Optimized geometries of these compounds show that they have no imaginary frequencies,and they are stable on the potential energy surface. The heat capacity and enthalpy of some typical compounds at different temperatures were obtained by statistic thermodynamics,and isodesmic reactions were designed for calculating standard enthalpies of formation for the derivatives of nitropyzarole. The average molar volume and theoretical density were estimated using the Monte-Carlo method based on 0.001 ebohr-3 densigy space. Furthermore,the detonation velocity and pressure of the derivatives were estimated by the Kamlet-Jacbos equation. Results show that the ring of pyrazole has some aromaticity and the detonation velocities of these compounds are between 6.42 and 9.00 kms-1. Detonation performances of these compounds show that they are very good candidates for energetic materials.

166. Numerical Simulation of Shock Initiation in Covered Comp B by Projectile Impact
CUI Kai-hua,HONG Tao and CAO Jie-dong, Chinese Journal of Energetic Materials,2010,18(3):286~289

Abstract: Based on the experiments of cylindrical flat nosed copper projectiles impacting Comp B with various thickness steel cover plates,the explosion processes of cylindrical flat and round nosed tungsten projectiles impacting Comp B with various thickness steel cover plates were simulated. The curves of critical velocity vs thickness of the steel cover plate were quantitatively analyzed. The results show that the calculational results of direct shock initiation satisfy Jacobs criterion to a larger extent. Furthermore,the relationship between flat and round nosed tungsten projectiles velocities were obtained,i. E. Vround ≈1.15Vflat. At last,the reason of the delayed detonation(XDT) events was analysed. The cause was attributed to the mutual effects between the damage of Comp B and the reflection shock.

167. Hexanitrohexaazaadamantane: A New Potential High-Energy-Density Compound Superior to Hexanitrohexaazaisowurtzitane (CL-20).
Xiao-Juan Xu1 [Department of Chemistry, Yancheng Teachers' College, Yancheng, Jiangsu, China], Wei-Hua Zhu2 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, Jiangsu, China], He-Ming Xiao2 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, Jiangsu, China], Journal of Energetic Materials; Oct-Dec2009, Vol. 27 Issue 4, p247-262

Abstract: To look for new high-energy-density compounds (HEDC) with good performance, molecular mechanics (MM) was first employed to predict the molecular spatial packings (or crystal structures) of hexanitrohexaazaadamantane (HNHAA) and the well-known high-energy-density compound hexanitrohexaazawurtzitane (ε-CL-20). Then, periodic ab initio calculations, using the GGA-RPBE method, were carried out on the band structures of the two predicted crystals. The results showed that they tended to crystallize in the same space group P21/c, and they have similar density of states (DOS) and comparable band gaps (ΔE, 3.546 and 3.522 eV for HNHAA and ε-CL-20, respectively), which presented similar thermal initiation mechanisms and comparable sensitivity. Furthermore, HNHAA was recommended as a new potential HEDC with better detonation properties than the well-known ε-CL-20, due to its larger density (2.315 gcm-3) than ε-CL-20 (2.173 gcm-3).

168. A Theoretical Study of Highly Nitrated Azacubanes.
Jinshan Li1 [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China], Hui Huang1 [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China], Yigang Huang1 [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China], Haishan Dong1 [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China], Journal of Energetic Materials; Oct2008, Vol. 26 Issue 4, p230-245

Abstract: The geometries of highly nitrated azacubanes have been fully optimized at the B3LYP/6-31 ++ G** theory level, and the gas phase enthalpies of formation have been obtained by designing the isodesmic reaction in which the azacubane cage skeleton is not destroyed. An efficient procedure for judging the driving force of detonation products of energetic compounds has been developed from the conservation of energy condition. The MP2/6-31 ++ G**//B3LYP/6-31 ++ G** atom-atom overlap-weighted NAO bond order shows that after the full nitration of 1,4-diazacubane and 1,3,5,7-tetraazacubane the weakest C-N bond on the 1,3,5,7-tetraazacubane cage skeleton strengthens slightly, but on the 1,4-diazacubane cage skeleton it weakens. For highly nitrated azacubanes, the introduction of -NH2 group results in the destabilization of the neighboring C-N bond on the cage skeleton. The shock stability of 2,4,6,8-tetranitro-1,3,5,7-tetraazacubane (TNTAzC) is superior to that of 2,3,5,6,7,8-hexanitro-1,4-diazacubane (HNDAzC). The detonation velocity and pressure for TNTAzC are predicted to reach 11.10 km/s and 101.7 GPa, respectively. The driving force of detonation products of HNDAzC is close to that of octanitrocubane, and the driving force of TNTAzC is about 4.0 times as large as that of the widely used high explosive HMX, showing that TNTAzC is a potential candidate of super high-energy compound

169. A Theoretical Study of Polynitropyridines and their N -oxides.
Jinshan Li1 [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China],Yigang Huang [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China], Haishan Dong1 [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China], Journal of Energetic Materials; Jul-Sep2005, Vol. 23 Issue 3, p133-149

Abstract: The geometries of polynitropyridines and their N-oxides have been optimized using the B3LYP density functional method and the 6-311++G** basis set. The accurate gas phase enthalpy of formation (at p = 1.013 × 10 5 Pa and T = 298.15 K) for pyridine and its N-oxide has been calculated employing the G3(MP2) method and the atomization scheme, and for polynitropyridines and their N-oxides at the B3LYP/6-311++G** level by designing the isodesmic reactions in which the pyridine ring maintains integral. Based on B3LYP/6-311++G** optimized geometries and calculated natural charges, this paper has calculated the crystal structures by the Karfunkel-Gdanitz method, and based on estimated solid enthalpies of formation and crystal densities has predicted the Chapman-Jouguet detonation velocities (D CJ ) by the Stine method. Calculated results show that for polynitropyridines and their N-oxides the introduction of ─NH 2 groups increases the strength of C─NO 2 bonds but reduces the gas phase enthalpy of formation. The least C─NO 2 bond order indicates that compounds 3,5-diamino-2,4,6-trinitropyridine and its N-oxide, whose D CJ values are predicted to be approximately 8.2 and 8.6 km/s, respectively, are most possibly low-sensitive or insensitive energetic materials. The largest D CJ value obtained in polynitropyridines and their N-oxides is about 9.5 km/s.

170. Theoretical Studies on Pentanitromono- acetylhexaazaisowurtzitane (PNMAIW) by AM1 and PM3 Methods.
Wu Yukai1 bjwujing@hotmail. Com [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, People's Republic of China], Ou Yuxiang1 [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, People's Republic of China], Liu Zhiguo1 [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, People's Republic of China], Chen Boren1 [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, People's Republic of China], Journal of Energetic Materials; Oct-Dec2003, Vol. 21 Issue 4, p261-273, 13p

Abstract: We use AM1 and PM3 semiempirical methods to conduct theoretical studies on possible polymorphs of pentanitromonoacetylhexaazaisowurtzitane (PNMAIW), and the close relationship, especially in sensitivity, between PNMAIW and four common nitramine explosives including hexanitrohexaazaisowurtzitane (HNIW) is set up. We forecast that the polymorphs of PNMAIW and HNIW are very alike, and the average real lengths of N-N, C-N and C-C bonds are 0.1403, 0.1455, and 0.1572 nm for A- and C-PNMAIW, 0.1393, 0.1453, and 0.1573 nm for B-PNMAIW, and 0.1396, 0.1452, and 0.1575 nm for D-PNMAIW. The heat of formation of PNMAIW in solid phase is about 152 kJmol<sup>-1</sup>. The impact and shock sensitivities of PNMAIW are predicted to be lower than that of HNIW.

171. Ab initio study on intermolecular interactions of energetic clusters
Xue-Hai Ju [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China]; He-Ming Xiao [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China], Journal of Energetic Materials, Volume 20, Issue 2 2002 , pages 153 – 164

Abstract: Ab initio SCF and Mller-Plesset correlation correction methods (MP2) in combination with counterpoise procedure for BSSE correction have been applied to R2N-NO2 (R=H, Me), hydrazine and difluoroamine clusters. Of all the stable structures found for each polymer with the same degree of polymerization, only the most stable one is reported. The corrected binding energies of the most stable clusters are predicted to be -32.93, -20.11, -24.68, -18.39 and -9.19 kJ/mol for dimers of nitramine, methylnitramine, dimethylnitramine (DMNA), hydrazine and difluoroamine, and -47.27 and -19.22 kJ/mol for trimers of DMNA and difluoroamine respectively. The proportion of correlated interaction energy to their total interaction energy for all clusters is at least 18.1 percent, and the BSSE of ?E (MP2) is at least 9.2 kJ/mol. Dispersion and/or electrostatic force are dominant in DMNA and difluoroamine clusters, whereas the H-bonds exist in nitramine, methylnitramine and hydrazine dimers. There exist cooperative effects in the trimers. As for R2N-NO2 dimers, the vibrational frequencies associated with N-O stretches or wags exhibit slight red shifts, but the modes associated with the motion of hydrogen atoms of the methyl group show somewhat blue shifts with respect to those of monomer. The N-H stretch mode exhibits large red shifts when it connects with other submolecules by H-bond as in the dimers of nitramine and hydrazine, otherwise it exhibits slight blue shifts.

172. Theoretical calculations of thermodynamic properties of chlorotetrazoles and nitrotetrazoles
Chen Zhaoxu [aDepartment of Chemistry, Nanjing university of science and technology, Nanjing, People's Republic of China]; Xiao Heming [aDepartment of Chemistry, Nanjing university of science and technology, Nanjing, People's Republic of China], Journal of Energetic Materials, Volume 17, Issue 4 December 1999 , pages 345 - 356

Abstract: Ab initio molecular orbital method was performed to calculate the enthalpies, heat capacities and entropies of chlorotetrazoles and nitrotetrazoles in the temperature range 100 -1000K. A scaling factor(0.90) for frequencies at HF/6-31G* level are proposed based on comparison of the calculated and the experimental thermodynamic data of 2H-tetrazole. The results show that chlorotetrazoles and nitrotetrazoles have similar thermodynamic properties respectively. Finally the heat capacity-temperature dependence in the form (a+bT+cT2) are presented by fitting the calculated heat capacity results.

173. An analysis of dynamic response of explosives due to impact and computer simulation of hot spot forming in explosives
X. P. Han [Dept. of Applied Mechanics, Northwestern Polytechnical University Xian, Shaanxi, P. R. C], L. X. Liab [Dept. of Applied Mechanics, Northwestern Polytechnical University Xian, Shaanxi, P. R. C, Dept. of Aircraft, Northwestern Polytechnical University], Y. C. Zhang [Dept. of Applied Mechanics, Northwestern Polytechnical University Xian, Shaanxi, P. R. C, Dept. of Mechanics, Xi an Jiaotong University], Journal of Energetic Materials, Volume 16, Issue 2 & 3 June 1998 , pages 187 - 197

Abstract: In accordance with the hot spot/initiation mechanism, the amendment of Perzyna's model of material behavior and elasto-viscoplastic analysis of explosive column due to impact are conducted in this paper. The flow parameter and Young's modulus are thought to be related with temperature. To test this developed model, the comparison between the experimental results and calculation values are done. The inhomogeneity of material is modeled by introducing a void at the center of the column. The numerical results show the elevated temperature near the voids. The effects of the shape and size of voids on local high temperature forming are also discussed.

174. AM1 studies on SN2 hydrolysis of methyl nitrate in alkaline solution
Gong Xuedong [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China]; Ling Yue [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China]; Xiao Heming [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China]

Abstract : The semi-empirical MO AMI method has been employed to investigate the mechanism of the alkaline SN2 hydrolysis of methyl nitrate and the influence of the solvent on the hydrolysis reaction. The activation energy calculated is 50.61 kJ/mol for the hydrolysis in gas phase, however when the solvent effect is taken into account, it is increased to 89.65 kJ/mol and in agreement with the experimental result(82.42 kJ/mol). It is shown that the solvation energy is an important source of the activation energy.

175. AM1 studies on the mechanism of hydrolysis of dinitro semi-glycoluril
Li Yumin [Department of chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China ]; Xiao Heming [Department of chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China], Journal of Energetic Materials, Volume 11, Issue 4 & 5 November 1993 , pages 311 - 324

Abstract: Theoretical calculations on the hydrolyses of dinitro semi-glycoluril in neutral, acidic and alkaline media, have been performed by using AMI method. The geometries of reactant, activated, and product complex for the hydrolysis processes have been fully optimized. Both in neutral and acidic media, activated complexes with four-membered ring structure have been obtained, and reaction-coordinate eigenvectors reveal their concerted feature of component processes involved. In contrast, in alkaline media, the hydrolysis is relatively easy, since it proceeds without activation of reactant complex, and the potential energy curve of this hydrolysis process obtained is also indicative of this. The calculated activation energies for the hydrolyses of dinitro semi-glycoluril in neutral and acidic media are 217. 233 kJ/mol and 218. 856 kJ/mol respectively.

176. Analysis on computation of kamlet parameter ф for CHNO explosive mixtures
Zhou Xing Xia [Department of Chemical Engineering, Beijing Institute of Technology, Beijing, China], Yu Yong Zhonga [Department of Chemical Engineering, Beijing Institute of Technology, Beijing, China], Journal of Energetic Materials, Volume 9, Issue 4 November 1991 , pages 283 - 296

Abstract: Kamlet parameter ф has been used to predict many explosive performances within applicable errors. There are three computation methods of ф for an explosive mixture in references: Kamlet's original definition of ф (as фI), by using weighted-average N, M and Q values of pure components (as фII) and by adding the weighted ф values of pure components (as фIII). In this paper, analysis shows that the three ф values can predict detonation velocity and detonation pressure within applicable accuracies over a broader range of chemical types for CHNO explosive mixtures. Note that фIII gives the best prediction results and has the simplest computation.

177. Prediction of Caged Polyaza Polynitroamine (Tetracyclo-HMX) as Energetic Compound.
Xue-Hai Ju1 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China], Zun-Yao Wang2 [School of Biological and Chemical Engineering, Jiaxing University, Zhejiang Jiaxing, P. R. China], Journal of Energetic Materials; Apr-Jun2009, Vol. 27 Issue 2, p133-143

Abstract: By fusing four HMX rings into a cage, a powerful nitroamine explosive was predicted. The heat of formation (HOF) of hetero pentacyclo-icosane nitro compound of dodecanitrododecaza-pentacyclo[9.5.1.13,9. 15,15. 17,13]icosane (DNDAPI or, alternatively, tetracyclo-HMX) was obtained by using density functional theory B3LYP method with 6-31G* basis set. The isodesmic reactions designed for the evaluation of HOF keep most of the basic ring structures of the title compounds and thus ensure the credibility of the result. The value of HOF is 1394.59 kJ/mol. The predicted detonation velocity of the title compound is 10.6 km/s and detonation pressure is 56.8 GPa, even at 90% of its theoretical density. These values are much larger than those of the widely used 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), indicating that DNDAPI is a promising candidate of high energy material. The dissociation energy for the N-NO2 bond in the cage skeleton of the title compound is 125.36 kJ/mol.

178. Theoretical Study of 2,4,6-Tris(3',5'-Diamino-2',4',6'-Trinitrophenylamino)-1,3,5-Triazine.
Xue-Hai Ju1 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, P. R. China], Zun-Yao Wang2[School of Biological and Chemical Engineering, Jiaxing University, Zhejiang Jiaxing, P. R. China], Journal of Energetic Materials; Jan-Mar2009, Vol. 27 Issue 1, p51-62

Abstract: The density functional theory (DFT) BLYP and B3LYP method with 3-21G* and 6-31G** basis sets were used to predict the structures, natural bond orbital (NBO) atomic charges, and ring interactions of 2,4,6-tris(3',5'-diamino-2',4',6'-trinitrophenylamino)-1,3,5-triazine (PL-1). Approximately, the molecule possesses C3 symmetry with three benzene rings tilted to the triazine plane. The interactions among three 3',5'-diamino-2',4',6'-trinitrophenylamino groups are of additivity. The heat of formation of PL-1 was estimated to be 427.6 J/mol via isodesmic reaction. Detonation velocity and pressure are 8.5 km/s and 35.5 GPa, respectively.

179. Theoretical Investigation of the Relationship between Impact Sensitivity and the Charges of the Nitro Group in Nitro Compounds.
Zhang Chaoyang1 [Institute of Chemical Materials, China Academy of Engineering Physics, Sichuan, People's Republic of China], Shu Yuanjie1 [Institute of Chemical Materials, China Academy of Engineering Physics, Sichuan, People's Republic of China], Huang Yigang1 [Institute of Chemical Materials, China Academy of Engineering Physics, Sichuan, People's Republic of China], Wang Xinfeng1 [Institute of Chemical Materials, China Academy of Engineering Physics, Sichuan, People's Republic of China], Journal of Energetic Materials; Apr-Jun2005, Vol. 23 Issue 2, p107-119

Abstract: By means of density functional theory (DFT), the general gradient approximation method (GGA), and the Beck LYP hybrid functional and DNP basis set, nitro group Mulliken charges (Q NO 2 ) are calculated and defined to assess and correlate with the impact sensitivities (H 50 ) of nitro compounds: very negative Q NO 2 and high H 50 . By calculating, analyzing, and comparing, we find that Q NO 2 can be regarded as a structural parameter to estimate impact sensitivity and has more availability in almost all nitro compounds in contrast to the length of the C&sbnd;NO 2 , N&sbnd;NO 2 , or O&sbnd;NO 2 bond R R&sbnd;NO 2 , molecular electrostatic potential (V mid ), and oxygen balance (OB). At the same time, it has good reliability and accuracy even though there are some exceptions. According to the data in this paper, the compound may be sensitive (H 50 = 0.4 m) when its nitro group has fewer negative charges than about 0.23.

180. Computational Study of Picric Acid and Potassium Picrate.
Xue-Hai Ju1 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, People's Republic of China], Xiao-Juan Xu1 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, People's Republic of China], He-Ming Xiao1 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, People's Republic of China], Journal of Energetic Materials; Apr-Jun2005, Vol. 23 Issue 2, p121-130

Abstract: The density functional theory (DFT) method at the B3LYP/6-311 + g** level was used for predicting the structures, natural bond orbital (NBO) atomic charges, thermodynamic properties, and IR spectroscopy of picric acid (PA) and potassium picrate (PP). The IR spectroscopies were assigned. The C–NO 2 bond is generally lengthier than all the other covalent bonds in both PA and PP, indicating that this bond is the weakest and prone to rupture in the decomposition process. The carbon atom that connects with oxygen atom in PP carries larger positive charges, and nitro oxygen atoms carry larger negative charges than the corresponding atoms in PA. The C–C populations of PP are more unevenly distributed than those of PA, indicating that the benzene ring of the former is less conjugated. Some C–C bonds in PP are much weaker. This weak C–C bond could be ruptured at the same time as the C–N bond in the initial decomposition process.

181. Theoretical Study on Thermodynamic and Detonation Properties of Polynitrocubanes
Xue-Hai Ju [Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094 (P. R. China], Zun-Yao Wang [School of Biological and Chemical Engineering, Jiaxing University, Zhejiang Jiaxing, 314001 (P. R. China], Propellants, Explosives, Pyrotechnics, 34: 106–109.

Abstract: We investigated the heat of formation (ΔfH) of polynitrocubanes using density functional theory B3LYP and HF methods with 6-31G*, 6-311+G**, and cc-pVDZ basis sets. The results indicate that ΔfH firstly decreases (nitro number m=0–2) and then increases (m=4–8) with each additional nitro group being introduced to the cubane skeleton. ΔfH of octanitrocubane is predicted to be 808.08 kJ mol−1 at the B3LYP/6-311+G** level. The Gibbs free energy of formation (ΔfG) increases by about 40–60 kJ mol−1 with each nitro group being added to the cubane when the substituent number is fewer than 4, then ΔfG increases by about 100–110 kJ mol−1 with each additional group being attached to the cubic skeleton. Both the detonation velocity and the pressure for polynitrocubanes increase as the number of substituents increases. Detonation velocity and pressure of octanitrocubane are substantially larger than the famous widely used explosive cyclotetramethylenetetranitramine (HMX).

182. An Ab Initio Theoretical Study of 2,4,6-Trinitro-1,3,5-Triazine, 3,6-Dinitro-1,2,4,5-Tetrazine, and 2,5,8-Trinitro-Tri-s-Triazine
Jinshan Li [Institute of Chemical Materials, China Academy of Engineering Physics, P. O. Box 919-311, Mianyang 621900, Sichuan (People's Republic of China], Propellants, Explosives, Pyrotechnics, 33: 443–447.

Abstract: In order to evaluate 2,4,6-trinitro-1,3,5-triazine (TNTAz), 3,6-dinitro-1,2,4,5-tetrazine (DNTAz), and 2,5,8-trinitro-tri-s-triazine (TNTsTAz), the geometries of these compounds have been fully optimized employing the B3LYP density functional method and the AUG-cc-pVDZ basis set. The accurate gas phase enthalpies of formation have been obtained by using the atomization procedure and designing isodesmic reactions in which the parent rings are not destroyed. Based on B3LYP/AUG-cc-pVDZ calculated geometries and natural charges, the crystal structures have been predicted using the Karfunkel–Gdanitz method. Computed results show that there exists extended conjugation over the parent rings of these compounds. More energy content is reserved in DNTAz than in both TNTAz and TNTsTAz. The title compounds are much more sensitive than 1,3,5-trinitrobenzene. The calculated detonation velocity of DNTAz reaches 9.73–9.88 km s−1, being larger than those of CL-20 and TNTAz. TNTsTAz has no advantage over the widely used energetic compounds such as RDX and HMX.

183. Computational Study on Potassium Picrate Crystal
Xue-Hai Ju, Ya-Lin Lu, Xiu-Fang Ma, He-Ming Xiao [Department of Chemistry, Nanjing University of Science & Technology, Nanjing, 210094, P. R. China], Propellants, Explosives, Pyrotechnics, 31: 290–293.

Abstract: DFT calculation at the B3LYP level was performed on crystalline potassium picrate. The frontier bands are slightly fluctuant. The energy gap between the highest occupied crystal orbital (HOCO) and the lowest unoccupied crystal orbital (LUCO) is 0.121 a. U. (3.29 eV). The carbon atoms that are connected with the nitro groups make up the narrow lower energy bands, with small contributions from nitro oxygen and phenol oxygen. The higher energy bands consist of orbitals from the nitro groups and carbon atom. The potassium bears almost 1 a. U. positive charge. The potassium forms ionic bonding with the phenol oxygen and the nitro oxygen at the same time. The crystal lattice energy is predicted to be −574.40 kJ/mol at the B3LYP level determined with the effective core pseudopotential HAYWSC-31G basis set for potassium and 6-31G** basis set for other atoms.

184. Computational Investigation on 2,4,6-Trinitrochlorobenzene Crystal
Xue-Hai Ju, Ling Qiu, He-Ming Xiao [Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, PR China], Propellants, Explosives, Pyrotechnics, 31: 38–41]

Abstract: Density functional theory calculations at the B3LYP level were performed on crystalline 2,4,6-trinitrochlorobenzene. The carbon, oxygen, and chlorine atoms make up the narrow lower energy bands, while the nitrogen, carbon, and oxygen atoms make up the higher energy bands. Besides, the contributions of these atomic orbitals to the frontier bands are somewhat well-proportioned. The Mulliken populations obviously demonstrate that the C-N bonds are the weakest, indicating that the C-NO2 is prone to rupture upon stimuli. An anisotropic impact on the bulk makes the electron transfer from chlorine to its neighbor carbon atom and from nitrogen atoms to oxygen atoms. The crystal lattice energy is predicted to be −50.99 kJ/mol, after being corrected for basis set superposition error.

185. QSPR Study for Estimation of Density of Some Aromatic Explosives by Multiple Linear Regression Approach
Feng Luan [Department of Applied Chemistry, Yantai University, Yantai 264005 (P. R. China], Huitao Liu [Department of Applied Chemistry, Yantai University, Yantai 264005 (P. R. China], Yingying Wen [Department of Applied Chemistry, Yantai University, Yantai 264005 (P. R. China], Qingzhong Li [Department of Applied Chemistry, Yantai University, Yantai 264005 (P. R. China], Xiaoyun Zhang [Department of Chemistry, Lanzhou University, Lanzhou 730000 (P. R. China], Jiazhong Sun [Department of Chemistry, Lanzhou University, Lanzhou 730000 (P. R. China], Propellants, Explosives, Pyrotechnics, 35: 169–174

Abstract: A quantitative structure-property relationship (QSPR) model was proposed on the basis of the molecular structure of 43 aromatic explosives and their density. The best linear model composed of five molecular descriptors which were selected from 522 constitutional, geometrical, topological, and quantum-mechanical types of descriptors. Statistical characteristics of the multiple linear model (R2=0.892, F=60.95, RMS=0.0539, AARD=2.41%) indicated satisfactory stability and predictive ability. The model may give some insight into the main structural factors that modulate the density of the investigated compounds.

186. A New Method for Evaluating the Energy Characteristics of C H N O Energetic Compounds.
Li, J. (2010) [Institute of Chemical Materials, China Academy of Engineering Physics, P. O. Box 919-311, Mianyang 621900, Sichuan (People's Republic of China], Propellants, Explosives, Pyrotechnics, 35: 182–185

Abstract: From the law of conversation of energy, the release energy from the initiation to the Chapman–Jouguet point during the detonation of an energetic compound has been deduced as a function of initial density, detonation velocity, and detonation pressure. For C H N O energetic compounds the relative release energy per unit volume (Iv) approaches the relative specific wall kinetic energy (Ecyl/EHMX) at 19 mm wall displacement from the cylinder test with HMX as reference. A good linear relationship between Iv and Ecyl/EHMX has been regressed, implying that Ecyl/EHMX is also a function of initial density, detonation velocity, and detonation pressure. It has been concluded that Iv can reflect the driving force of detonation products of energetic compounds and is appropriate to be used for the evaluation of energy characteristics. The assessment of the energy for a series of synthesized and theoretically designed high-energy compounds reveals that the future of C H N O energetic compounds is promising after CL-20 and ONC.

187. Investigation of the Correlations Between Nitro Group Charges and Some Properties of Nitro Organic Compounds
Chaoyang Zhang [Laboratory of Material Chemistry, Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), P. O. Box 919-327, Mianyang, Sichuan 621900 (P. R. China], Propellants, Explosives, Pyrotechnics, 33: 139–145.

Abstract: The so-called nitro group charge method (NGCM) is successfully established to investigate some properties of nitro compounds including the molecular stability measured by total energy (only for isomers), the bond lengths, bond dissociation energies (BDE), and the nitrating activities, in that the method considers the molecular structure. These properties are intrinsically and especially thermodynamically consistent with each other and can be well related qualitatively and even quantitatively with nitro group charges (QNitro). The correlations between QNitro and the properties are: (1) for nitro isomers, the more negative the average QNitro, the lower the total energy and the more stable is the isomer; (2) for any separate group of nitro compounds, the more negative QNitro, the shorter the R-nitro bond length; (3) for the bond dissociation energy, more negative QNitro corresponds to a higher BDE of the R-nitro bond; (4) by NGCM, the conditions, the reaction rates and the occurrence ratios of products of some nitration can be predicted and compared: the more negative QNitro of the product, the easier and faster the nitration, and the higher the occurrence ratio of the corresponding product.

188. Molecular Dynamics Simulations of Polymer-Bonded Explosives (PBXs): Modeling, Mechanical Properties and their Dependence on Temperatures and Concentrations of Binders
Jijun Xiao1, Xiufang Ma1, Wei Zhu1, Yucheng Huang1, Heming Xiao1 [Chemical Engineering Institute, Nanjing University of Science and Technology, Nanjing 210094 (P. R. China],Hui Huang2, Jinshan Li2 [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900 (P. R. China], Propellants, Explosives, Pyrotechnics, 32: 355–359.

Abstract: Two models, i. E. “covering” and “cutting” models, for the polymer-bonded explosives (PBXs) were proposed for different researching aspects. Used for choosing polymeric binders, the “covering” models are mainly applied to find the relations of temperatures and concentrations respectively with elastic properties of the PBXs. The “cutting” model is especially used to describe the highly anisotropic behavior of 1,3,5-triamino-2,4,6-trinitrobenzene crystals (TATB). These models were realized by using molecular dynamics methods. It is found that the ductility of crystalline TATB can be effectively improved by blending fluorine-containing polymers in small amounts. The moduli for the PBXs decrease with increase in temperature and concentration of binders. Different crystalline surfaces interacting with the same polymer binder have different modulus-decreasing effects due to the highly anisotropic behavior of TATB. The modulus-decreasing effect for different crystalline surfaces ranking order is (010)≈(100)>(001).

189. A Detonation Model of High/Low Velocity Detonation
Shaoming Hu, Chenfang Li, Yunhua Ma, Junmin Cui [Xian Modern Chemistry Research Institute, Xian, 710065 (P. R. China], Propellants, Explosives, Pyrotechnics, 32: 73–79.

Abstract: A new detonation model that can simulate both high and low velocity detonations is established using the least action principle. The least action principle is valid for mechanics and thermodynamics associated with a detonation process. Therefore, the least action principle is valid in detonation science. In this model, thermodynamic equilibrium state is taken as the known final point of the detonation process. Thermodynamic potentials are analogous to mechanical ones, and the Lagrangian function in the detonation process is L=T−V. Under certain assumptions, the variation calculus of the Lagrangian function gives two solutions: the first one is a constant temperature solution, and the second one is the solution of an ordinary differential equation. A special solution of the ordinary differential equation is given.

190. Calculation of Detonation Velocity, Pressure, and Electric Sensitivity of Nitro Arenes Based on Quantum Chemistry
Guixiang Wang, Heming Xiao, Xuehai Ju, Xuedong Gong [Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094 (P. R. China], Propellants, Explosives, Pyrotechnics, 31: 361–368.

Abstract: The DFT-B3LYP method, with basis set 6-31G*, is employed to optimize molecular geometries and electronic structures of thirty-nine nitro arenes. The averaged molar volume (V) and theoretical density (ϱ) are estimated using the Monte-Carlo method, based on 0.001 electrons/bohr3 density space and a self-compiled program. The detonation velocity (D) and pressure (P) of the explosives are estimated by using the Kamlet–Jacbos equation on the basis of the theoretical density and heat of formation (ΔfH), which is calculated using the PM3 method. The reliability of this theoretical method and results are tested by comparing the theoretical values of ϱ and D with the experimental or referenced values. The theoretical values of D and P are correlated with the experimental values of electric sensitivity (EES). It is found that, for the nitro arenes, there is a linear relationship between the square of detonation velocity (D2) or detonation pressure (P) and electric sensitivity (EES), which suggests that such a theoretical approach can be used to predict or judge the magnitude of EES, which is difficult to measure in the molecular design of energetic materials. In addition, we have discussed the influence of the substituted groups and the parameters of the electronic structure on density, detonation velocity, pressure, and electric sensitivity, and have shown that the substituted groups have the effect of activity or insensitivity, and that the influence of Q-NO2 and ELUMO is important.

191. Relationship between the Bond Dissociation Energies and Impact Sensitivities of Some Nitro-Explosives
Xiao-Shu Song1 [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, (P. R. China, School of Physics and Chemistry, Guizhou Normal University, Guiyang 550001, (P. R. China], Xin-Lu Cheng2, Xiang-Dong Yang2 [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, (P. R. China], Bi He3 [Institute of Chemical Materials, CAEP, Mianyang 621900, (P. R. China], Propellants, Explosives, Pyrotechnics, 31: 306–310.

Abstract: The bond dissociation energy (BDE) for removal of the NO2 group for eleven CHNO nitro-containing explosive molecules is studied to find its correlation with impact sensitivity. The BDE for removal of the NO2 group in nitroaromatic molecules with nitro alkyl, and esters with nitro alkyl, is calculated using the B3LYP method of Density Functional Theory with the 6-31G* basis set. The relationship between the impact sensitivities and the weakest C-NO2 bond dissociation energy values is examined. The results indicate a nearly linear correlation between the impact sensitivity and the ratio of the BDE value to the total molecular energy.

192. Detonation Velocities and Pressures, and their Relationships with Electric Spark Sensitivities for Nitramines
Gui-Xiang Wang, He-Ming Xiao, Xiao-Juan Xu, Xue-Hai Ju [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210094, P. R. China], Propellants, Explosives, Pyrotechnics, 31: 102–109.

Abstract: The DFT-B3LYP method, with basis set 6–31G*, is employed to optimize molecular geometries and electronic structures of eighteen nitramines. The averaged molar volume (V) and theoretical density (ρ) are estimated using the Monte-Carlo method based on 0.001 electrons/bohr3 density space. Subsequently, the detonation velocity (D) and pressure (P) of the explosives are estimated by using the Kamlet-Jacobs equation on the basis of the theoretical density and heat of formation (ΔfH), which is calculated using the PM3 method. The reliability of this theoretical method and results are tested by comparing the theoretical values of ρ and D with the experimental or referenced values. The theoretical values of D and P are compared with the experimental values of electric spark sensitivity (EES). It is found that for the compounds with metylenenitramine units ( CH2N(NO2) ) in their molecules (such as ORDX, AcAn and HMX) or with the better symmetrical cyclic nitramines but excluding metylenenitramine units (such as DNDC and TNAD), there is a excellent linear relationship between the square of detonation velocity (D2) or the logarithm of detonation pressure (lg P) and electric spark sensitivity (EES). This suggests that in the molecular design of energetic materials, such a theoretical approach can be used to predict their EES values, which have been proven to be difficult to predict quantitatively or to synthesize.

193. Theoretical Calculation and Molecular Design for High Explosives: Theoretical Study on Polynitropyrazines and Their N-oxides
Jinshan Li, Yigang Huang, Haishan Dong [Institute of Chemical Materials, China Academy of Engineering Physics, P. O. Box 919-311, Mianyang, Sichuan 621900 (People's Republic of China], Propellants, Explosives, Pyrotechnics, 29: 231–235.

Abstract: The geometries of polynitropyrazines and their N-oxides have been fully optimized employing the density functional B3LYP method and the 6-31++G** basis set. For polynitropyrazines and their N-oxides we have obtained the enthalpies of formation (at p=1.013×105 Pa and T=298.15 K) by designing isodesmic reactions and the detonation velocities by using the Stine method. Calculated results show that the aromaticity of the pyrazine ring of polynitropyrazine is lower than that of its N-oxide. From the acquired relationship between the experimental impact sensitivity H50 (12B type) and the least C NO2 bond order the predicted H50 values for compounds 2,5-diamino-3,6-dinitropyrazine and 2,5-diamino-3,6-dinitropyrazine-1-oxide are 83 cm and 59 cm, respectively, implying that they are low sensitive explosives. The enthalpy of formation of polynitropyrazine is much less than that of its N-oxide. The calculated density (1.90 g/cm3) for 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is close to the experimental value (1.918 g/cm3), and from both sensitivity and detonation velocity it has been deduced that LLM-105 is superior to other diaminodinitropyrazines and their N-oxides. The largest density and detonation velocity obtained in this work are 2.02 g/cm3 (2-amino-3,5,6-trinitropyrazine) and 9.34 km/s (2,3,5,6-tetranitropyrazine), respectively.

194. Ab Initio Calculation of BN Generation from Boron and Nitrogen Oxides
Zhong Wang1, Shu Fen Li1, Li Min Zhang1 [Laboratory of Bond-Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (P. R. of China], Zhen Yu Sheng2, Shu Qin Yu2 [Abdus Salam International Centre for Theoretical Physics, 34014 Trieste, Italy, Laboratory of Bond-Selective Chemistry, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (P. R. of China], Propellants, Explosives, Pyrotechnics, 29: 160–165.

Abstract: Boron Nitride (BN) is one of the products produced in the burning of boron-containing propellant. A possible reaction mechanism for the reactions of boron and nitrogen oxides (NO, NO2, N2O) has been studied using the G2MP2 method. The BN product can be formed in the reactions of B(4P) with NO, NO2 and N2O. Among these three reactions, B(4P)+NO2 and B(4P)+N2O are 181.42 kJ/mol and 160.92 kJ/mol more-exothermic than the B(4P)+NO reaction. The barrier heights from intermediates to transition states are 64.85 kJ/mol and 111.75 kJ/mol for B(4P)+NO2 and B(4P)+N2O, respectively. However, in the reaction B(4P)+NO , the transition from intermediate to product (IM3→BN+O) is very endothermic by 420.70 kJ/mol. So B(4P)+ N2O→BN+NO and B(4P)+NO2→BN+O2 are more likely reactions to generate BN than B(4P)+NO→BN+O.

195. Theoretical Studies on PNMFIW by AM1 and PM3 Methods
Wu Yukai, Ou Yuxiang, Liu Zhiguo, Chen Boren [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (P. R. China], Propellants, Explosives, Pyrotechnics, 28: 281–286.

Abstract: AM1 and PM3 semi-empirical methods were used to conduct theoretical studies on possible polymorphs of pentanitromonoformylhexaazaisowurtzitane (PNMFIW), and a close link between PNMFIW and Hexanitrohexaazaisowurtzitane (HNIW), especially in sensitivity, is shown. The optimized geometries of possible polymorphs of PNMFIW are similar to those of HNIW. PNMFIW in ε-HNIW prepared from tetraacetyldiformylhexaazaisowurtzitane is predicted to have a D-form. The average N N bond lengths of PNMFIW computed by AM1 and PM3 methods are shorter than those of HNIW. The differences in energy and thermochemistry values between PNMFIW and HNIW are insignificant except molecular energies 255.75 kJ⋅mol−1 for D-form PNMFIW and 460.36 kJ⋅mol−1 for ε-HNIW. Based on a Mulliken population analysis of the N N bonds, the impact sensitivities of A-, B-, C- and D-forms of PNMFIW are estimated to be lower than those of the corresponding polymorphs of HNIW. Taking into account all N N bond lengths and overall molecule size, the shock sensitivities of all forms PNMFIW are predicted to be almost the same, and lower than those of HNIW.

196. Acceleration and Viscoplastic Deformation of Spherical and Cylindrical Casings under Explosive Loading
Duowang Tan, Chengwei Sun, Yanping Wang [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, CAEP, P. O. BOX 919, Mianyang, 621900, P. R. China], Propellants, Explosives, Pyrotechnics, 28: 43–47.

Abstract: A theoretical model to predict continuous deformation and acceleration of spherical or cylindrical metallic casings driven by detonation products inwards or outwards before fracture occurring is proposed in this paper. The casing materials are assumed to be rigid viscoplastic medium and the geometries are one dimension i. E., the explosive charge is initiated at the spherical center or on the cylindrical axis in the divergent case, or uniformly on the explosive shell's outer surface in the convergent case. The acceleration movements of spherical and cylindrical casings calculated with this model are in good agreement with experimental and numerical results performed with the finite element hydrocode DYNA2D. It is concluded that this model describes well one-dimensional divergent and convergent movements of spherical or cylindrical casings under explosive loading, and provides a useful method to explore related problems, such as shell's fragmentation, its maximum velocity before fracture, blast wave in the near area adjacent to the casing and solid liner implosion.

197. Ab Initio Study on Interactions in Difluoroamine Clusters from one to four Molecules
Xue-Hai Ju, He-Ming Xiao [Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094 (P. R. China], Propellants, Explosives, Pyrotechnics, 27: 320–326.

Abstract: Ab initio calculations at HF, MP2 levels of theory with 6-311G* basis set in combination with counterpoise procedure for BSSE correction have been performed on difluoroamine clusters consisting of up to four molecules. The dimer, trimer and tetramer were all found to exhibit two minima. There are two types of clusters: cyclic and chain. The corrected bond energies are 9.19, 19.22 and 33.67 kJ/mol at the MP2/6-311G*//HF/6-311G* level for the more stable dimer, trimer and tetramer, respectively. The contribution of cooperative effect to the interaction energy is quite significant in the cyclic clusters, but negligible in the chain ones. There exist H-bonds which involve six and eight F⋅⋅⋅H contacts at ca. 0.23–0.24 nm in cyclic trimer and cyclic tetramer, respectively. The intermolecular interaction is an exothermic process under 400.0 K accompanied by a decrease in the probability of complex formation, and the interactions become weak as temperature increases.

198. A Study on the Intermolecular Interaction of Energetic System—Mixtures Containing –CNO2 and –NH2 Groups
Li Jinshan1,2 [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210094 (People's Republic of China, China Academy of Engineering Physics, Chengdu, 610004 (People's Republic of China],Xiao Heming, Dong Haishan2 [China Academy of Engineering Physics, Chengdu, 610004 (People's Republic of China], Propellants, Explosives, Pyrotechnics, 25: 26–30.

Abstract: The fully optimized geometries of model systems of CH3NO2+NH3 with ab initio method at the HF/6-31G* level were obtained, and the intermolecular interaction energy was calculated with MP4 electron correlation correction and with the basis set superposition error correction by Boys–Bernardi “counterpoise” method. Additionally, PM3 MO method was employed to study the intermolecular interaction of TNB (1,3,5-trinitrobenzene) with TATB (1,3,5-triamino-2,4,6-trinitrobenzene), and the intermolecular interaction energy was given with approximation of correlation interaction energy by dispersion energy. The computed results show that the intermolecular interactions affect slightly the strength of C-NO2 bonds of CH3NO2 and TNB. The greatest intermolecular interaction energies of CH3NO2 with NH3 and of TNB with TATB are −18.64 and −31.85 kJ/mol, respectively.

199. Theoretical Study on Tetrazole and its Derivatives: 4. Ab Initio Study on Hydroxyl Derivatives of Tetrazole
Chen Zhaoxu, Xiao Heming [Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094 (People's Republic of China], Propellants, Explosives, Pyrotechnics, 24: 319–324.

Abstract: Ab initio MO calculations at MP2/6-31G* level were performed on hydroxyl derivatives of tetrazole and their anions. Their fully optimized geometries, electronic structures, IR spectra and thermodynamic functions are reported. The calculation results show that all the titled compounds are practically planar and aromatic. The N4 atom on the ring is most negatively charged. The N-hydroxytetrazoles are more stable than the C-hydroxytetrazoles. The thermodynamic properties of the titled compounds are similar.

200. Theoretical Estimation for Unreacted and Reacted States of Composite Propellant
Fu-Hu Su, Sheng-San Cheng [Chung Shan Institute of Science and Technology, Lungtan, Taiwan 32526(Republic of China], Propellants, Explosives, Pyrotechnics, 23: 193–199.

Abstract: Pertaining to the computer modeling for analyzing bullet or fragment impact sensitivities of solid rocket motors, the input parameters of JWL Equation to describe the unreacted and reacted states of solid propellants are inevitable. To obtain the parameters by experiments is complicated and expensive. This work proposes a theoretical method, including Rodean's theory and the additivity principle, to estimate the unreacted states of composite propellants. First, Rodean's theory and the additivity principle are appraised to be utilizable by the experimental data of homogeneous explosives and composite explosives; then they are applied to estimate the unreacted states of two composite propellants. The theoretical estimations for the unreacted states of the composite propellants are consistent with the experimental results depicted in the literature. With the Marquardt's nonlinear modeling method, the estimated states can be modeled into JWL Equation for gaining the relative parameters. In addition, the modified TIGER code is applied to evaluate the reacted states of one nitramine composite propellant and detonation properties of PBXW-115.

201. Theoretical Studies on the Mechanism of Hydrolysis of Nitroguanidine by AM1 Method
Xiao Heming, Li Yumin, Li Yongfu[Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210014(P. R. China], Propellants, Explosives, Pyrotechnics, 23: 23–27.

Abstract: The mechanism of hydrolysis of nitroguanidine has been studied theoretically. The molecular geometries have been fully optimized at AM1 level of theory for reagent, activated and product complexes for hydrolysis of nitroguanidine in neutral, acidic and alkaline media, respectively. In neutral and acidic media, both activated complexes have four-membered ring structures, and the reaction-coordinated eigenvectors show heavy-atom reorganization and proton transfer to be truly concerted in both cases. In alkaline medium, the hydrolysis also involves activated complex. The calculated activation energies for the hydrolysis of nitroguanidine in neutral, acidic and alkaline media are 278.2 kJ/mol, 330.2 kJ/mol and 213.0 kJ/mol, respectively.

202. Theoretical Study on Pyrolysis and Sensitivity of Energetic Compounds. Part I: Simple model molecules containing NO2 Group
Xiao Heming, Fan Jianfen, Gong Xuedong [Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210094 (P. R. China], Propellants, Explosives, Pyrotechnics, 22: 360–364.

Abstract: UHF (Unrestricted Hartree-Fock) Molecular Orbital calculations have been first performed for studying the pyrolysis mechanism of five compounds (nitromethane, methyl nitrate, nitroamine, methyl nitroamine and dimethyl nitroamine) containing NO2 group as the simple models of organic explosives by using PM3 and AM1 methods. The potential energy curves and activation energies of the five pyrolysis reactions (into radicals) have been obtained. The activation energies are consistent with the experimental impact sensitivity of these three kinds of explosives: C-nitro < N-nitro < O-nitro compounds. It is found that there is a parallel linear relationship between the bond orders of N NO2 bond in the molecules of three nitroamine compounds and the activation energies of their initiation reactions breaking N NO2 bond. The obtained correlation coefficients between bond orders and activation energies from PM3 and AM1 calculations are 0.9962 and 0.9999, respectively.

203. Relationships between Electron Structures of N-Methylolamines and their Reactivity in the mannich reaction
Yuejun Zhang, Wei Dong, Jie Shi, Weimin Li [School of Chemical Engineering, East China Institute of Technology, Nanjing 210014 (China], Propellants, Explosives, Pyrotechnics, 19: 103–106.

Abstract: The electron structures of various unstable N-methylolamines and their imine cations formed during the urotropine nitrolysis process were studied by SCF-CNDO/2 computation. The relative tendency of forming imine cations from such N-methylolamine molecules was assessed by the computation values of Mulliken bond order (Mco) of C O bond and the negative values (−Eco) of two-atome energy. The electrophilic order of imine cations described by the products (Zco) of carbocation's static charges and the rations of partition functions Qs/Qp between s and p electrons, were used to express the relative reactivity of the Mannich reaction intermediates. Experimental results were satisfactorily explained by the calculated values, and the reactivity of nitrolysis fragments was successfully predicted by the defined values.

204. Molecular orbital studies of the thermal decomposition mechanism of dimethylnitramine
Yue Ling, Ze-Hua Tang [Department of Chemistry, East China Institue of Technology, Nanjing 210014 (P. R. China], He-Ming Xiao,† [*Correspondence: He-Ming Xiao, Department of Chemistry, East China Institue of Technology, Nanjing 210014 (P. R. China, †This work is financially supported by the National Natural Science Foundation of China], Propellants, Explosives, Pyrotechnics, 17: 116–119.

Abstract: The electronic structures of dimethylnitramine (DMNA) were calculated using ab initio Gaussian 80 program at the Hartree-Fock level with STO-3G and STO-4-21G basis set, respectively. The Mulliken bond order of the N NO2 bond is the least one in comparision with those of the other bonds in the DMNA molecule. Two potential energy curves along the N N bond splitting pathway (RN N) were obtained using MINDO/3 and MNDO methods, respectively. These curves have the same trend and are qualitatively consistent with the results obtained from the thermolysis of nitromethane (CH3NO2). It was found that the frontier MO levels and the net charges of groups are changed with RN N distance. The products of thermal decomposition and the energy changes were calculated by MINDO/3 method and are discussed in this paper.

205. A Study on Thermodynamic Functions of Detonation Products
Wu Xiong [Xian No. 3 Chemical Industrial Institute, Xian (China], Propellants, Explosives, Pyrotechnics, 10: 47–52.

Abstract: Thermodynamic parameters of detonation products were calculated using functions based on the enthalpy H0 − H . The results are compared to the experimental data and discussed with respect to other methods. Within the same temperature range the accuracy was considerably improved. The coefficients for the thermodynamic functions of detonation products are given in an appendix.

206. Calculations of Derivative of Second Virial Coefficients based on the exp-6 intermolecular potential†
Wu Xiong, Sun Jian [Xian Modern Chemistry Research Institute, Xian (China], Propellants, Explosives, Pyrotechnics, 13: 48–51.
†Projects supported by China National Nature Science Fund.

Abstract: The quantity of the partial derivative of second virial coefficients with respect to temperature in reduced form, T*∂B*/∂T* has been computed for an exp-6 intermolecular potential

The results are tabulated over the reduced temperature range T* from 0.4 to 400, and for seven values of the parameters α from 12 to 15. The outputs lead us to lay the foundation for the applications of the theoretical virial type equation of state (6) like VLW using the best form exp-6 for high pressure studies.

207. The neural network prediction Explosive Velocity

Wang Guodong, Liu Cun, Cui Lei. "Explosive", 2007, (2) : 39-42

Abstract: This calculation of explosive molecules of 30 oxygen balance (OB), charge density (ρ), the concentration carbon atoms nC/Vm, the concentration of hydrogen atoms nH/Vm, the concentration of oxygen atoms nO/Vm, the concentration on nitrogen atoms nN/Vm 6 parameters to the six kinds of parameters as the explosive molecular structure descriptors, the construction of artificial neural network model to predict explosive detonation velocity. Forecast results show that the predicted value and literature value of the maximum relative error is 5.35%, minimum 0.53%, indicating that neural network to determine the quantitative relationship can be well used to predict the explosive detonation velocity.