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Combustion

1. Combustion Characteristics of Gun Propellant under the Arc Plasma in Air

ZHANG Yu-cheng, ZHAO Xiao-mei, YAN Wen-rong, LIU Yi, ZHANG Jiang-bo, LI Qiang
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: In order to study the interaction mechanism between plasma and propellant, the change rules of the surfaces for three typical propellants and an ETPE propellant exposed to the arc plasma with different discharge intensity in air were studied with SEM. The mass of the propellant which took part in the reaction with plasma was obtained. The results show that the energy input of the arc plasma in air had a significant effect on the ignition of propellant. The mass of reacted propellant would increase with increasing of energy input. There was a great difference between the reacted surface of ETPE propellant and the typical propellants.For the relative degree of propellant being sensitive to the arc plasma, the double base propellant is the strongest and the ETPE propellant is the weakest.

2. Effects of Copper Salts on Combustion Characteristics of RDX-CMDB Propellant

FAN Jun-guan, FU Xiao-long, YU Hong-jian, ZHANG Xiao-hong, FAN Xue-zhong
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effects of six copper salts, including DBC, CNI, NT-Cu, B-Cu, S-Cu, A-Cu, and the mixture of copper and carbon black on the combustion characteristics of RDX-CMDB propellant were studied in detail. The quenched surfaces for the propellant were analyzed by SEM and elemental analyses. The results show that the copper salts can decrease the combustion pressure exponent of the propellants in the pressure range of 16-22MPa. The copper salts and the mixture of copper and carbon black unobviously affect combustion characteristics of RDX-CMDB propellant in the pressure range of 10-22MPa. Copper salts and the mixtures of copper salts and carbon black can promote RDX-CMDB propellant combustion further.

3. Combustion Characteristics of Multilayer Gun Propellant

WEI Lun, WANG Qiong-lin, LIU Shao-wu, ZHU Yang-chun, GUO Feng, ZHENG Shuang
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The influence of the structures on the progressive burning of multilayer gun propellant disk was discussed and the theoretical Γ-Ψ curves were obtained by a established combustion model of the multilayer gun propellant disk, and the static burning behaviors of the multilayer propellant with diffrerent structures were studied by the closed bomb test. The results show that the trends of multilayer gun propellant experimental curves are similar to the trends of multilayer gun propellant theoretical curves while propellant burned mass was in 0.2～0.8;too large(or too small) K and X has a negative impact on progressive burning of the multilayer propellant, and only within reasonable choice, will the progressive burning of the multilayer propellant get better;The characteristic of constant surface burning is present and progressive burning of the multilayer propellant becomes better with the width to its intial thickness W rising.

4. Deflagration to Detonation Transition Process in Aluminum Dust-air Mixture

Xiao-dong1, LIU Qing-ming2, BAI Chun-hua2, WANG Jing-yu1
1. College of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China
2. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China

Abstract: Ignition, flame acceleration and deflagration to detonation transition in fine flake aluminum dust-air mixture under weak ignition of 40J was studied in a horizontal tube with an inner diameter of 199mm and length of 29.6m and equiped with 40 sets of special dust dispersion system. The influences of aluminum dust concentration and ignition delay time on the deflagration to detonation transition(DDT) process of aluminum dust-air mixture were discussed. The experimental results show that the whole DDT process of aluminum dust-air mixture can be divided into slow reaction compression stage and fast reaction shock stage.With the ignition delay time of 370ms and aluminum dust concentration of 300g•m3, the dimensionless transition distance from ignition point to the detonation wave formed in aluminum dust-air mixture is 83 times L/D ratio, and detonation occurs with a peak overpressure of 9.8MPa and velocity of 1670m•s-1. Self-sustained detonation wave of aluminum dust-air mixture is characterized by the existence of spin detonation structure. The front wave velocity and overpressure of self-sustained aluminum dust-air mixture oscillate with the propagation distance.

5. Experimental Study on Deflagration-to-detonation Transition in Pressed High-density Explosives

WANG Jian, WEN Shang-gang, HE Zhi, WANG Jun
Laboratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics, CAEP, Mianyang Sichuan 621900, China

Abstract: The characteristics of deflagration-to-detonation transition(DDT)in the pressed high-density explosives with mass fraction of 95% and dnsity of 1.86g•cm-3 was measured using electrical pins and pressure sensors. The effect of amount of black power and confinement condition on DDT process of pressed high-density explosive was studied. The results show that it is very difficult to obtain the apparent transition in the pressed explosives and the transition of the pressed explosive is little affected with the change of the mass of black powder which increased from 1.5g to 3.0g. The phenomenon of deflagration-to-detonation transition is achieved under the strong confinement condition in the explosive and the detonation-induced distance is about 545mm.

6. Conception and Principle of Controlled Burning Gun Propellant

WANG Qiong-lin, LIU Shao-wu, ZHANG Yuan-bo, YU Hui-fang, YAO Yue-juan, WANG Feng, ZHU Yang-chun, GUO Feng, WEI Lun
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: From the point of view of enhancing the burning progressivity and total energy of gun propellant, a new conception gun propellant and charge i. E. Controlled burning gun proellant(CBGP)and charge have been put forward.With the help of the data obtained by closed bomb test and interior ballistic test, three important formulae are obtained. The formulae show that the gun propellant with high muzzle velocity should satisfy the requirement of high energy and high burning progressivity at the same time and the correctness of CBGP conception was vertified.

7. Combustion Characteristics of ETPE Propellant with Plasma Ignition

ZHAO Xiao-mei, YU Bin, ZHANG Yu-cheng, YAN Wen-rong
Xi'an Modern Research Institute, Xi'an 710065, China

Abstract: In order to solve the problem of the long delay time of ignition and the difficulty in ignition of ETPE propellant, the ETPE propellant was ignited by the electrical arc plasma which was generated by plasma producer via high power pulse electrical power. The ignition and combustion characteristics of ETPE propellant was studied under the effect of plasma. The results indicated that in comparison with general way of ignition, the plasma effect made the burning rate of the ETPE propellant enhance evidently, and the delay time of ignition shorten, and the consistency of ignition improved, considering that the shortening of the delay time of ignition and enhancing of the initial burning rate are caused by the strong effect of plasma flow with high-temperature and high-speed. This effect causes RDX grain leaping over the process of heat-absorbing and liquating and entering into the process of decomposing and heat-release rapidly.

8. Constant-volume Combustion Properties of Combustible Cartridge Case

LI Yu1, ZHAO Cheng-wen1, GUO De-hui2, ZHOU Wei-liang1, XU Fu-ming1
1. School of Chemistry and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
2.Xi'an North Huian Chemical Co., Ltd, Xi'an 710302, China

Abstract: The effect of different charge density, different ignition pressure and different moisture on the combustion properties and energy release properties of combustible cartridge case was studied through closed-bomb test. The results show that as the charge density and the ignition pressure increase, the cartridges burning rate and the maximum pressure increase, the combustion stability is improved and energy of cartridges releases more sufficient. The effect of charge density on energy release decreases with increasing the ignition pressure. Strong hygroscopicity of combustible cartridges is verified through absorption experiment of moisture. When samples contain moisture, the burning rate and the combustion stability of low charge density decrease significantly, and the combustion duration extends, however, the influence on impetus is weak.

9. A Combustion Model of Multilayer Disc Gun Propellant

WEI Lun, WANG Qiong-lin, LIU Shao-wu, ZHU Yang-chun, GUO Feng, ZHANG Yuan-bo
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: A combustion model of multilayer disc high energy nitramine propellant was established to simulate and improve its interior ballistic property and burning behavior. Three parameters:the burning rate ratio of the slow layer to fast layer of the disc(K), and the ratio of the intial thickness of the slow layer to the fast layer of the disc(X), the ratio of the internal diameter and external diameter diffirence to the intial thickness of the disc(W), were defined. The Ψ-Z curves describing the shape functions of the multilayer disc gun propellant with different parameters were obtained and the combustion model was validated by the interrupted-burning test. The results show that X, K and W have great influence on the burning of multilayer disc propellant, and Ψ-Z curves also change regularly. The interrupted-burning test result proves that the combustion model is simple and hypotheses are reasonable and the theoretical calculation is very closed to the test results.

10. Hot-Spot Effect of Local Defects in Shocked Sapphire Crystal

ZHENG Xian-xu, WANG Rong-bo, TAN Duo-wang, ZHAO Jun, HE Zhi, HE Li-hua, LIU Cang-li
Laboratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics, CAEP, Mianyang Sichuan 621900, China

Abstract: Explosive materials is replaced by sapphire crystal and a defect induced hot-spot is fabricated in the sapphire crystal by femtosecond laser ablation. The optical radiation and temperature of hot-spot are measured by pyrometer, and this measurement results can be used to analyze the formation and prapagation of hot-spot. The results demonstrate that the more intensed optical radiation and higher temperature will be emitted from the hot-spot in shocked heterogeneous sapphire than that in the shocked homogeneous sapphire. The growth and decay of the hot-spot is very fast and the total duration of the hot-spot is about 200 nanoseconds. A novel experimental method for further studying the formation and prapagation of hot-spot in explosive materials is established.

11. A Quantitative Assessment Method of Gun Propellant Combustion Progressivity Based on Closed Bomb Test

WANG Qiong-lin1, ZHAO Xiao-feng2, LIU Shao-wu1, ZHANG Yuan-bo1, YU Hui-fang1, YAO Yue-juan1, ZHU Yang-chun1, WEI Lun1
1.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2.Military Representative Office of Missle Device, Xi'an 710065, China

Abstract: Through comparing the combustion process of gun propellant by dynamic interior ballistic cycle with static closed-bomb test, an ideal gun propellant with special progressivity distribution is found.Based on the difference of progressivity distribution between an ideal and a real gun propellant, a quantitative assessment method of gun propellant progressivity based on closed-bomb test has been proposed. The testing results show that the assessment results well accord with the data of interior ballistic cycle.

12. Interrupted Combustion Experiment of SF-3 Propellant with Plasma Ignition

ZHANG Yu-cheng, LI Qiang, ZHANG Jiang-bo, JIANG Shu-jun, YAN Wen-rong, ZHAO Xiao-mei, WANG Gu-tai
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Two comparative tests related to combustion performance and interruption combustion were carried out with a vented chamber under the conditions of plasma ignition and regular ignition. The changes of burned surface were examined with SEM. The results indicated that there were a lot of micro holes on the burned surface after the propellant had been ignited by a bottom jet plasma generator. The existed micro holes increased burning area on the surface of propellant, and led to a deviation of the SF-3 propellant burning with plasma ignition from the geometric burning rule to a certain extent. The unitized contents of Cu, C, O elements on the interrupted combustion surface of SF-3 propellant are different under two ignition conditions. The unitized contents of the three kinds of elements were 0.7%, 30.0% and 69.3% respectively under the regular ignition condition, however 3.0%, 35.5% and 61.5% respectively under the plasma ignition condition. This difference showed that the combustion performance of SF-3 propellant could be affected evidently by the high temperature particles of C and Cu which were produced by the plasma generator.

13. Interior Ballistic Performance of the Sheet Multilayer Propelling Charge

ZHANG Jiang-bo, ZHANG Yu-cheng, WANG Qiong-lin, JIANG Shu-jun, ZHAO Xiao-mei, YAN Wen-rong, LI Qiang
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The sheet multilayer propelling charge was made. The inner of the charge was made of high energy propellant with higher burning rate and the outer one was made of low burning rate propellant containing macromolecular deterrent material. The sheet multilayer charge with different content of deterrent material and different layer constructions was investigated by closed bomb test and 30 mm simulation gun shootong. The experimental results show that MD1 and MD2 multilayer charge containing different contents of deterrent both have good progressive combustion performance and MD2 is better than MD1, the muzzle velocity of MD1 with outer-to-inner layer thickness ratio of 1 ∶ 10 increases 77.4 m • s-1 than that of 5/7 single base propellant, the muzzle velocity of MD2 with thickness ratio of 1 ∶ 5 increases 108.7 m • s-1 than that of 5/7 single base propellant while keeping max pressure almost constant. The results also show that by changing deterrent content in the outer layer and the ratio of the outer-to-inner layer thickness of the sheet multilayer propellant, the effect of increasing the total charge mass and so as to raise the muzzle velocity without maximum pressure increment could be expected.

14. Analysis of Abnormal Interior Ballistic Performance of an Equilibrium Launcher at High and Low Temperature

YUN Lai-feng1, 2, RUI Xiao-ting1, FENG Ke-hua3
1. School of Power Engineering, Nanjing University of Science & Technology, Nanjing 210094, China;
2.Military Representative Bureau in Nanjng of General Armament Department of PLA, Nanjng 210024, China
3.Jiangsu Yongfeng Machinery Co.Ltd, XuYi Jiangsu 211722, China

Abstract: The reasons of abnormal interior ballistic performance of an equilibrium launcher at high and low temperature are analyzed.Interior ballistic equations of an equilibrium launcher are established, its interior ballistic performance is computed at normal, high and low temperature respectively.By analyzing the computation and test results and test phenomenon, pointing out that abnormal performance at low temperature is caused by the severe fracture of propellant produced in ignition process and the brittleness of propellant at low temperature. The abnormal performance at high temperature is caused by the decrease of initial burning area because of propellant softening at high temperature and felting of propellant patches. The two phenomena and their randomicity affect the probable error of muzzle velocity, especially the propellant fracture at low temperature may be the hidden trouble to launch safety, considering that the propellant of the weapon system should be replaced by another material with good temperature performance.

15. Application of High Energy Density Compounds CL-20, DNTF and ADN in High Energy Propellant

WEI Lun, WANG Qiong-lin, LIU Shao-wu, ZHU Yang-chun, GUO Feng, ZHANG Yuan-bo
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: To apply the high energy density compounds(HEDCs) in high energy and high burning rate propellant widely, the influence of CL-20, DNTF and ADN on the compatibility, energy and burning behavior of nitramine propellant RGD7A was studied by closed bomb test and VST. The results show thatthe compatibility of CL-20 and DNTF with RGD7A is excellent. CL-20 and DNTF make the energy and density of nitramine propellant increase.In comparison with RGD7A propellant, the burning rate and pressure exponent of nitramine propellant containing CL-20 DNTF increased under the champer pressure 40-240MPa.

16. Detonation Wave Characteristics of Dual Explosive under Asymmetrical Initiation

DING Gang, YUAN Bao-hui
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The characteristics of detonation wave in dual explosive under asymmetrical initiation was studied. The shape of the detonation front, the t vs.d coordinate and the shape distribution of the detonation wave was gained by the slit scan technique of rotating mirror camera. The velocity distribution, the formed reason of the concave detonation front and the spread rule of the detonation convergence wave were analyzed. The detonation front is convergent shape of bow wave and it can accelerate the detonation velocity of the inner explosive.

17. Power of Aluminized Explosives with Different Diameters

HAN Yong, HUANG Hui, HUANG Yi-min, LU Xiao-jun, GUAN Li-feng, JIANG Zhi-hai, GAO Da-yuan
Institute of Chemical Materials, CAEP, Mianyang Sichuan 621900, China

Abstract: In order to study the deviation extent from the similarity law about the energy released process of aluminized explosives with different diameters, the cylinder tests of two aluminized explosives with diameters of 50mm and 100mm were performed by a slit scanning photography technique with a high speed rotating camera. The slit was located at 200mm for explosive with Ф50mm and 300mm for explosive with Ф100mm apart from the rear end of cylinder. The experiment result shows that the expansion velocity of Ф100mm cylinder is five percent higher than that of Ф50mm cylinder, the ratio energy of Ф100mm cylinder is eleven percent higher than that of Ф50mm cylinder at the similar expansion position.It reveals that the similarity law of the cylinder expansion velocity does not recur for the two aluminized explosives, which is true for ideal explosives. The power of large size aluminized explosives would be underestimated by the small size cylinder test.

18. Combustion Physical Model of Potassium Perchlorate Composite Powder

CHEN Xiao-ming1, CHEN Zhi-hui2, ZHENG Lin1, ZHANG Kuo1, YAN Wen-rong1
1.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2.Military Representative Office of NO.845 PLA, Xi'an 710065, China

Abstract: The combustion characteristics of potassium perchlorate composite powder were studied by DSC, electron microscope scan and burning test in closed-bomb. The results show that the burning rate pressure exponent of the powder decreases obviously when the pressure increases. The burning rate will be unchanged when the pressure comes to a constant value.It shows a burning rate-pressure(u-p) platform phenomenon obviously. The pressure exponent is bigger at-40℃, and the u-p platform phenomenon does not appear. The burning process was analyzed thoroughly based on the physical configuration and combustion characteristics of this kind of powder. The combustion physical model of potassium perchlorate composite powder was presented, and the combustion mechanism was explained.Based on the combustion mechanism the u-p characteristics and the different combustion characteristics between high and low temperature of the powder were expounded.

19. The Energy Release Law of Propellant Based on Relative Pressure Impulse

Lü Bing-feng, XIAO Zhong-liang, ZHANG Li-hua, LIU You-ping
School of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China

Abstract: The correctional model of relative pressure impulse format is established by analysing and correcting the geometric combustion law for studying propellant actual energy release law. Theoretical and experimental analysis under the conditions of various loading density, propellant, constant volume and variational volume are made. The results show that the actual energy release law is embodied in correctional model. The theory and scheme established by correctional model is reasonable.

20. Influence of Ammonium Perchlorate and Aluminum Powder on the Combustion Characteristics of AP-CMDB Propellant

LI Ji-zhen, FAN Xue-zhong, LIU Xiao-gang
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The influences of particle size and content of ammonium perchlorate(AP) and aluminum powder(Al) on the combustion characteristics of AP-CMDB propellant are experimentally studied by determining the burning rates and pressure exponents of the propellant at different pressures. The results show that the smaller granule AP and the larger granule Al powder make the burning rates of AP-CMDB propellant increase effectively, and the smaller granule AP and Al make the pressure exponents in the pressure range of 10-20MPa increase.When the mass fraction of Al powder is lower than 14%, the combustion characteristics of AP-CMDB propellant are not obviously affected by the contents of AP and Al.When the mass fraction of Al powder is higher than 14%, the burning rates of AP-CMDB propellant are decreased because of the incomplete combustion of Al.

21. Damage Characteristics of Propellant Charge of Composite Perforating Device

JING Zhen-yu
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The HTPB/AP composite propellant loaded in the composite perforating device was taken as a chief object.By the simulated tests acted under different loads, the damages of the propellant charge samples were simulated.With the measuring technique for the density of propellant grain and closed bomb test, the damage level of the samples was analyzed and the combustion characteristics of the damaged propellant charge was studied. The results show that under different loads acted on the HTPB/AP composite propellant, a microcosmic change and damage occurs in its internal structure.Its damage level is successively in high velocity impact, low velocity impact, quasi-static compression and high temperature impact. The more serious the damage level, the greater the change of the combustion characteristics. Under the high velocity impact and low velocity impact, the combustion characteristics of the composite propellant becomes convective combustion or compressive combustion. Under the condition of a certain environmental restriction, it is possible that the deflagration to detonation transition may occur.

22. Correlation between PDSC Characteristic Value and Burning Rate for the Solid Propellants

LIU Zi-ru1, LIU Yan2, ZHAO Feng-qi1, ZHANG La-ying1, YIN Cui-mei1
1.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2.Beijing Chemical Defense Research Institute, Beijing 102205, China

Abstract: The characteristic values of PDSC(high pressure differential scanning calorimetry) for 32 propellants, including DB, CMDB, XLDB and NEPE, were correlated with burning rates by an empiric formula u =ku1/2.For the formula, p is pressure, △Sd =△Hd/(Te-To), △Hd is decomposition heat, To and Te are onset and end temperatures of heat release on DSC curve, respectively. The results show that the good fittings of the formulas for all tested propellants appear in pressure range(≤7MPa) of PDSC so far.It is found that ku, correlation factor of burning rate with PDSC characteristic value, can be used to study the effect of burning catalysts and the influence of component on burning rate for the propellants.

23. Effects of Aluminum Powder Content on Exhaust Signature of CMDB Propellant

ZHANG Xiao-hong1, 2, ZHAO Feng-qi2, TAN Hui-min1
1. School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
2.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effects of aluminum powder content on exhaust signature of CMDB propellant, such as visible, infrared and laser transmissivity, infrared radiant temperature and radiance, were studied by using transmitter, thermal-image instrument, FTIR spectrum device and high-speed camera etc. The results show that the visible, infrared and laser transmissivities of exhaust plume of CMDB propellant are greatly decreased, while the infrared radiant temperature, radiance and dimension of flames are obviously increased as the content of aluminum powder increases in the formulation of CMDB propellant.It was also observed that the content of aluminum powder has slight influences on the types of final combustion products of CMDB propellant.

24. Influence of Metal Salicylates on the Combustion Characteristics and Thermal Behavior of AP-CMDB Propellant

LI Ji-zhen, FAN Xue-zhong, ZHENG Xiao-dong, LIU Xiao-gang, ZHANG La-ying
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The influence of lead(II) salicylate(PbSa), copper(II) salicylate(CuSa), bismuth(II) salicylate(BiSa), lead(II) methylene-bissalicylate(Pb2Sa2), copper(II) methylene-bissalicylate(Cu2Sa2) and lead(II) copper(II) methylene-bissalicylate(PbCuSa2) on the combustion characteristics and thermal behaviors of the AP-CMDB propellants were experimentally studied. The results showed that the pressure exponents of the AP-CMDB propellants decreased in a certain extent with the increase in burning rates of the propellants at low pressures and the decrease in burning rates at high pressures. The peak temperature of thermal decompositions of binary system NC/NG in the AP-CMDB propellants were affected obviously by all the metal salicylates, and the peak temperature of thermal decompositions of AP at high temperature were brought forward obviously by CuSa and Cu2Sa2.It was also found that the pressure exponents of the AP-CMDB propellants in the wide pressure range of 1～20MPa can be decreased efficiently by the copper(II) salts of salicyle(CuSa, Cu2Sa2 and PbCuSa2).

25. Effect of Organic Lead Salts on Combustion Characteristics and Thermal Decomposition of High Energy Modified Double Base Propellants

FU Xiao-long, FAN Xue-zhong, LI Ji-zhen, LIU Xiao-gang, ZHANG La-ying
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effect of three organic lead salts, including lead 3-nitro-1, 2, 4-triazol-5-onate, lead sallcylate and lead stearate, on combustion characteristics and thermal decomposition of high energy modified double-base(HEMDB) propellant were studied at various pressures. The results show that the effect of organic lead salts on the combustion characteristics and DSC characteristics values of HEMDB is obvious.Lead 3-nitro-1, 2, 4-triazol-5-onate, lead sallcylate and lead stearate can accelerate the thermal decomposition of RDX in HEMDB propellant. The burning rate and DSC characteristics values of the HEMDB propellant increase as pressure increases. The burning rate of HEMDB propellant was found to be related to the DSC characteristics values of HEMDB propellant in the pressure range from 1MPa to 10MPa.

26. Research on Mutilayer Disc Nitramine Gun Propellant

WANG Qiong-lin, LIU Shao-wu, ZHU Yang-chun, GUO Feng, ZHANG Yuan-bo, WEI Lun
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: A new mutilayer disc nitramine gun propellant was developed and prepared. The effect of slow burning materials on the burning rate of high energy nitramine gun propellant was studied by the constant-pressure burning rate test and closed bomb test. Combustion stability of mutilayer disc nitramine gun propellant was studied by rupture combustion tests. The results show that slow buring materials can decrease the burning rate of propellant and enhance its progressive combustion preformance effectively. The 30mm interior ballistic test showed that compared to reference nitramine mutiperforated propellant, mutilayer disc nitramine gun propellant can increase muzzle kinetic energy of 15%.

27. Interactional Mechanism of the Interface Between CL-20 and Some Bonding Agents

ZHANG Bin, LUO Yun-jun, TAN Hui-min
School of Material Science and Technology, Beijing Institute of Technology, Beijing 100081, China

Abstract: The properties of CL-20 crystal coating with four bonding agents and interaction mechanism of the interface between them are studied by XPS and MIR. The results indicate that a layer of viscous film of bonding agent on the surface of CL-20, the induction effect of the nitro group in CL-20 molecule on the functional group of bonding agent are formed, proving that bonding agent is available for coating CL-20.

28. Effect of Copper Compounds and Carbon Black on the Combustion Characteristics of Smokeless NEPE Propellants

ZHANG Wei, LI Ji-zhen, SUN Yu-kun, FAN Xue-zhong
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effect of two copper compounds (AD and BC) and three carbon black on combustion characteristics of smokeless NEPE propellant are studied by determining the combustion characteristics of propellant at different pressures and analyzing the composition of elements on quick quenched surface. The results show that the suitable amount of AD (an organic copper compound) can improve the combustion characteristics of the propellant and reduce the pressure exponents of the propellant to less than 0.45 in the pressure range of 3～(20MPa). The catalysis of AD is weaker than that of the same quantity of BC (an organic copper compound) in the pressure range of 12～18MPa, the reason might be that the content of copper from AD on the combustion surface is lower than that from BC on the combustion surface. Three carbon materials can change the burning rate of the propellant in the pressure range of 3～18MPa. Increasing added quantity of ethyne carbon in the propellants can enhance the burning rate and lower the pressure exponent of the propellant in the pressure range of 3～20MPa.

29. Research of HTPB/AP Composite Propellant Shock Wave Ignition

LEI Wei-guo, WU Quan-dao, WEI Guo-ping, YUAN Tie-gang, HUO Hong-xing
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The influence of shock wave on the detonation performance of HTPB/AP composite propellant used in plus penetrator is studied by means of clapboard experiments. The results show that the HTPB/AP composite propellant can be detonated reliably by means of reasonably controlling the shock wave intensity. A new method is provided for the initiation of other propellants.

30. The Catalytic Combustion of DB Propellant with Low Burning Rate and Low Flame Temperature

QIN Neng~(1, 2), WANG Liang~1, XIE Bo~2 , TIAN Chang-hua~2
1. College of Astronautics, Northwestern Polytechnical University, Xi'an 710072, China
2. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The combustion performance, thermal decomposition, and quenched surface appearance and element distribution of double-base (DB) propellant containing general lead and copper salt catalysts with low burning rate and low flame temperature were investigated. The following experimental phenomena were observed: (1) the elements distribution of quenched samples surface were not uniform, and element C and catalysts existed accumulation to some degree; (2) the quenched surfaces of samples containing catalysts appeared different balls, and different catalysts formed the balls with different diameter distribution, the main compositions of the balls were Pb elements, and the others were small amount of other elements and these balls connected to form long chain and short branch one another; (3) the uncombustion surfaces of samples with or without catalysts had no balls. The results indicated that general lead and copper salt catalysts used in common DB propellants also had catalytic effect on DB propellant with low burning rate and low flame temperature, and also have great effects on thermal decomposition.

31. Mechanical Sensitivity and Combustion Properties of CMDB Propellant Containing PSAN

DANG Yong-zhan, ZHAO Feng-qi
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The mechanical sensitivity and combustion properties of CMDB propellant using phase stabilized ammonium nitrate(PSAN) as oxidizer were investigated through the burning rate, impact sensitivity and friction sensitivity measurements. The experimental results show that PSAN is effective for improving the sensitivity of CMDB propellant, the burning rate of CMDB propellant with PSAN is lower than that of CMDB propellant with RDX, and the pressure exponent of CMDB propellant with PSAN is higher than that of CMDB propellant with RDX. With increasing the PSAN content in CMDB propellant, the burning rate decreases, and the pressure exponent increases in the pressure range of 1 to 5 MPa.

32. The Combustion Characteristics of RDX Modified Double Base Spheric Small Size Propellants

CAI Sheng, WANG Ze-shan
Chemical Engineering School, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The grain distribution and thermal decomposition characteristic of RDX in RDX modified double base spheric small size propellants are discussed. The combustion mechanism of RDX modified double base spheric small size propellants is presented. The combustion properties of the RDX modified small size propellants are determined by a closed vessel and analyzed theoretically. The results show that the decompositions of RDX and double-base groups in modified double base spheric small size propellants are carrying through independently. With the improvement of the pressure, the burning rate of the modified double base spheric small size propellants will be higher than that of remodeled double base spheric small size propellants.

33. Detonation Performance of TATB、TCTNB and TCDNB

GAO Da-yuan~1, XU Rong~1, DONG Hai-shan~1, LI Bo-tao~1, Lü Chun-xu~2
1.Institute of Chemical Materials, CAEP, Mianyiang 621900, China
2. School of Chemical Engineering, NUST, Nanjing 210094, China

Abstract: The detonation velocity and pressure of Ф20mm cylinder TATB、TCTNB/Wax (97%/3%) and TCDNB/Wax (97%/3%) have been measured by ionization probes and manganin gauge, and their detonation parameters and the equilibrium composition of detonation products at C-J state have been computed by means of the VLWR code. The testing results show that the detonation velocity and pressure are 7.452 mm•μs~(-1) and 24.40 GPa for TATB, (6.890) mm•μs~(-1) and 20.28 GPa for TCTNB and 5.973 mm•μs~(-1) and 15.30 GPa for TCDNB respectively. The calculated results were close to experimental values, showing that the calculated results are satisfactory.

34. The Thermal Decomposition and Combustion of a New Type High Energy Polymer GAP

WANG Tian-fang, LI Shu-fen
Department of Chemical Physics, University of Science and Technology of China, Hefei230026, China

Abstract: The research process and the status of the applications of GAP are summarized. The experimental studies of the thermal decomposition and the combustion of GAP are introduced, and the calculation studies of the combustion products of GAP are also mentioned. The results are compared and discussed in a certain extent. Some new effective investigating methods, such as GCMS, pyrolytic MS, MBMS, IR/UV/CO_2 laser-induced decomposition, laser-supported decomposition, etc, are presented.

35. Effects of Types of Lead Compounds on the Combustion Characteristics of Smokeless NEPE Propellants

FAN Xue-zhong, ZHANG Wei, LI Ji-zhen, SUN Yu-kun
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effects of three kinds of lead compounds on the combustion characteristics of smokeless NEPE propellant were investigated by Crawford bomb test and elemental analyses of quenched surface of propellant samples. The used lead compounds were LF (an energetic lead compound), LP (an organic lead compound) and LC(an inorganic lead compound), respectively. The propellant samples, containing LF, LP and LC, were prepared by slurry casting process. It was found that those lead compounds all could decrease the pressure exponents of the propellant to 0.33～0.48 in the pressure range of 3～5MPa and to 0.18～0.58 in the pressure range of 5～12MPa, respectively. LP, which also had no side effect on the curing process of the propellant, can obviously improve the combustion characteristics of smokeless NEPE propellant in the pressure range of 3～12MPa. The results of elemental analyses indicated that the content of lead on the combustion surface of propellant containing LF or LP is more enriched than that of the propellant containing LC.

36. Principle and Realizable Approach of Variable Burning Rate Propellant

XIAO Zhong-liang, HE Zeng-di, LIü You-ping, MA Zhong-liang, LU Bing-feng
Department of Chemical Engineering, North University of China, Taiyuan 030051, China

Abstract: According to the interior ballistic performance of guns, a concept of variable-burning rate propellant was put forward, the fundamental principle of this propellant was discussed and the technologic way to realize the principle was explained.In order to realize the variable-burning rate , the propellant has two layers , inner layer's burning rate is higher than the outer layer's. The results show that two-layered variable-burning rate propellant has wishful discharge rule and good properties of progressive combustion. The propellant has the advantages of high energy, universal applicability and high security.

37. Progress of Study on Method of Diagnosing the Combustion Mechanism of Solid Propellant

DING Li, ZHAO Feng-qi, XU Si-yu
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The progresses in the method, equipment and investigation results of diagrosing the thermal decomposition of energetic material and combustion wave structure of propellant were introduced. Are reviewed with 16 references.Meanwhile, the results in this field by these means were reported. The development direcation of research on combustion mechanism was discussed.With the development of new and sophisticated method and techniques, the diagnosis techniques and appliacement in this field should be improved for obtaining the effective message to understand the combustion mechanism exactly.

38. Effect of Components on Combustion and Mechanical Properties of HTPB Propellant with High Energy

CHEN Sheng, LIU Yun-fei, YAO Wei-shang
School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China

Abstract: The combustion properties and mechanical properties of HTPB propellant with 90% solid mass fraction were studied by changing the content and particle size of oxidizer AP, bonding agent and the value of R. The results show that the energy of HTPB propellant increases with the increase of the solid content, and the combustion properties and mechanical properties also keep in a good state. Under the condition of high solid mass fraction, the combustion and mechanical properties of HTPB propellant display some distinct rules as the change of the directions for producing chemicals. The propellants combust steadily and the burning rate and pressure exponent can be controlled.Its burning rate-pressure exponent is between 0.30 and 0.40. The mechanical properties are tested at three different temperatures: 60℃, 25℃ and-40℃, revealing that the maximum tensile strength of the propellant at the three temperatures is larger than 1.0 MPa and the maximum elongation of HTPB propellant at-40℃ can reach 74.7%.

39. Influence of Different Catalyzers on Decreasing Burning-rate Pressure Exponent of Double-base Propellant

LIAO Xin, MA Fang-shen, DU Ping, WANG Ze-shan
Department of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: In order to discuss technical approach of decreaing burning-rate pressure-exponent of propellant, a method of decreaing burning-rate pressure-exponent of double-base propellant by additiving catalyzer has been studied.Nine catalyzers are selected. The burning-rate pressure-exponent of double-base propellant containing the catalyzers is measured and disposed in terms of segment. The law of depressing burning-rate pressure-exponent of double-base propellant with different catalyzers at different pressure interval is discussed. The results show that different catalyzers at different pressure interval have different effects in decreaing burning-rate pressureexponent of double-base propellant, the general trend is that in low pressure interval it has more obvious effects.Of nine catalyzers studied, nano-mCuO and Pb3O4 catalyzers can decrease burning-rate pressure-exponent of double-base propellant obviously.

40. Effect of Combustion Catalysts on the Combustion Properties of TEGDN Gun Propellant

ZHAO Feng-qi, XU Si-yu, ZHENG Lin, YI Jian-hua, GAO Hong-xu, CHEN Xiao-ming, HAO Hai-xia, LI Shang-wen
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Some catalysts are putting into TEGDN gun propellants and the effect of these catalysts on combustion properties of TEGDN gun propellant is studied through closed bomb test. The result shows that, certain combustion catalyst can decrease the pressure exponent of part of combustion pressure region of TEGDN gun propellant, the pressure region decreased is related to the kind of catalysts.Lead phthalic acid can shorten combustion time, improve burning rate and increase combustion gas generation brisance of TEGDN gun propellant. Copper salt can depress the combustion gas generation brisance of TEGDN gun propellant.

41. A New Correcting Method for Pressure Curve in the Whole Burning Process of Propellants in Closed Bomb Test

YING San-jiu, XIAO Zheng-gang, XU Fu-ming
Department of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: Two factors resulting in pressure loss in closed bomb test were discussed. A new correcting method for pressure loss was established in light of theoretical equation used for pressure loss correcting and the pressure-time curves measured in closed bomb tests, and the temperature-time curve of vessel wall is unnecessary. Established method can interpret the effects of gas thermodynamical parameters and covolume on pressure loss in closed bomb. Compared with the conventional correcting methods for pressure loss, the new method can obtain not only the propellant force and covolume, but also the pressure curves and burning rate curves in the whole burning process of propellants.Results of closed bomb tests show that the new established method is simple and practical.

42. The Combustion Properties of HTPB Propellants under High Pressures

SONG Ji-ge, ZHANG Zhan-quan, LIU Bing
Inner Mongolia Synthetic Chemical Engineering Institute, Huhehaote 010010, China

Abstract: In order to improve the combustion properties of HTPB propellants, the effect of carbonate composites, ferrocene derivative G, high-nitrogen energetic material M, nanometer metal oxide particles and nano-aluminum on combustion characteristics of HTPB propellants was studied. The results show that carbonate composites decreased the burning rate and pressure exponent of HTPB propellants. The ferrocene derivative G decreased the pressure exponent of HTPB propellants to 0.27 in the pressure range of 8.60-17.12MPa, and increased their burning rate.High-nitrogen energetic material M decreased both the burning rate and the pressure exponent of HTPB propellants.Modifier M and G decreased the pressure exponent of HTPB propellants to 0.24 in the pressure range of 8.63-16.48MPa.Nano aluminum and nano-metal oxide obviously decreased the pressure exponent of HTPB propellants.

43. Effect of the Reliability of Coating Layer on the Measurement of Burning Rate of High Buring Rate Propellant and Improved Methods

ZHENG Lin, ZHAO Hong-li, CHEN Xiaoming, ZHAO Feng-qi
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The burning rates of the propellants grain coated by silicon rubber at the pressure range from 30 to 80 MPa were measured by the Crawford test. The results indicated that the burning rates of the propellants were increased significantly during the combustion process. The abnormal increasing of the burning rates at high-pressure range was caused by the debonding between the propellant and the inhibitor at high-pressure and the erosive burning of the propellant grain.It was found that the modified propellant grain inhibited with inorganic inhibiting layer by applying improved inhibiting technology, appears reliable inhibiting and steady combustion at high pressure.It was pointed out that the application of the inhibiting materials with low thermal conductivity coefficient and reliable bonding effect is the key technique for ensuring the measurement accuracy of burning rates of the propellant in high pressure range.

44. Factors Influencing Pressure Exponent of Boron-Based Fuel-Rich Propellant

WU Wan-e1, 2, MAO Gen-wang1, HU Song-qi1, WANG Ying-hong1
1. College of Astronautics, Northwestern Poly-technical University, Xi'an 710072, China
2. The Second Artillery Engineering Institute, Xi'an 710025, China

Abstract: In order to obtain the main factors affecting the pressure exponent of boron-based fuel-rich propellant, propellant samples were prepared via mix of the compositions in mixing machine, pouring in vacuum and curing at constant temperature. The burning rate of propellants was determined by strand target method, and the pressure exponent was obtained from u=apn. The experimental results indicate that the pressure exponent is affected by HTPB content, AP content and gradation and catalyst content to a certain extent. The pressure exponent will increase as HTPB content and AP weight mean diameter decrease, while AP content and catalyst content increase.

45. Effect of Extrusion and Fracture of Gun Propellant Charge on Combustion Behavior

XU Jin-xiang
Beijing Univerisity of Science and Technology, Beijing 100081, China

Abstract: In order to determine the relations between combustion behavior of propellant charges and its extrusion process, a dynamic simulating device is adopted to prepare samples of propellant charges which have been pressed with different dynamic high pressure and fractured subsequently. The combustion behaviors of samples have been tested in closed bomb and the burning law was studied.It is found that the initial phase of combustion for fractured samples has been boosted up, and the latter phase of combustion corresponding to high pressure region has been weakened reversely. The fracture of propellant charge owe to high pressure enduring has bad effect on launch-safety.

46. Effects of NGu on the Combustion Performance of Nitramine Propellants Containing RDX

ZHANG Zou-zou, JIANG Shu-jun, ZHANG Yu-cheng, YANG Yan
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: To investigate from micro angles the effects of NGu on the pressure exponent change of burning rate of nitramine propellant containing RDX, the quenched experiments of gun propellants with RDX and NGu were carried out by rapid chamber depressurization in an ignition-and-combustion simulator under the pressure about 35 MPa. The burned surfaces of the quenched propellant samples were observed by SEM. The results show that the balance state between deflagration of RDX and melted layer of the propellants has an influence on the change of burning rate pressure exponent. The melted layer formed on the surface of the nitramine propellants containing NGu can restrain the deflagration of RDX.When the mass ratio of RDX and NGu is less than 1.0, the burning rate pressure exponent of the propellants will reduce obviously. There is an acerous crystal on the combustion-ending surface when the propellants have ingredients of RDX and NGu.

47. Effect of Novel Energetic Composite Catalysts on Combustion Properties of Minimum Smoke Propellant

ZHAO Feng-qi, GAO Hong-xu, LUO Yang, WANG Bai-cheng, GAO Yin, LI Shang-wen
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: In order to investigate the effect of novel energetic catalysts on the combustion properties of minimum smoke propellant, the RDX-CMDB propellant samples containing various energetic composite catalysts were prepared through a solventless extrusion technique. The propellant burning rates at different pressures were measured by a strand burner and the experimental data were treated and analyzed with a linear regression method. The results show that in the energetic catalysts studied, lead salt of 2-hydroxy-3, 5-dinitropyridine(2HDNPPb)/copper salt of 2-hydroxy-3, 5-dinitropyridine(2HDNPCu) and lead salt of 4-hydroxy-3, 5-dinitropyridine(4HDNPPb)/2HDNPCu composite catalysts possess better catalytic effect and ability to reduce pressure exponent for the propellant.In comparison with single energetic lead salt or copper salt, the mixtures of lead and copper salts of hydroxypyridines have higher catalytic efficiency when the total content of catalyst added is constant.

48. Effects of Physical Dimension on Combustion Performance of Tubular Variable-burning-rate Gun Propellant

ZHANG Li-hua, MA Zhong-liang, LIU You-ping, HE Zeng-di, Lü Bing-feng, XIAO Zhong-liang
School of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China

Abstract: The effects of physical dimension(inner diameter and length-to-diameter ratio) on the combustion performance of a tubular variable-burning-rate gun propellant were investigated by closed bomb test. The difference between theoretical and experimental Γ-Ψ curves was compared and analyzed. The experimental results show that this gun propellant would not present good progressive combustion performance when its inner diameter is too large or too small.When the length-to-diameter ratio is less than 2, it has an obvious adverse effect on progressive combustion, and the suitable value of length-to-diameter ratio is 2.5 as considering the comp-rehensive effects of combustion property and packing density. The main reason for the difference between theoretical and experimental Γ-Ψ curves was that some postulated conditions assumed in the derivation process of theoretical equations can not be met in experimental test.

49. The Experimental Study on Deflagration-to-Detonation Transition in Modified Double-base Propellant with ACP

DONG Shu-nan1, WANG Shi-ying1, ZHU Jin-Sheng2, YAO Bao-xue1
1.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
2. Air Force Military Representative Office in Shijiazhuang Region, Handan Hebei 056028, China

Abstract: To study the effect of ACP, a fast burning energy material, on the deflagration-to-detonation transition(DDT) in the modified double-base propellant, the experimental study of DDT process of propellant under the condition of porous charge is carried out with the testing system established by the DDT tube. The positon-time relationship and the stress wave shape for the front of deflagration and detonation are recorded using the ionization probes and piezoelectric stress sensors. The experimental results of the propagation velocity of wave front, the location of the detonation transition point and the pressure in different positions of the charge bed are calculated and compared. The results show that the fast burning material ACP can increase the transition tendency of the modified double base propellant to DDT.When the percentage of ACP variates from 5% to 7%, the tendency of the transition from deflagration to detonation in charges increases obviously.

50. Deflagration to Detonation Transition Characteristics of NEPE Propellant

ZHAO Xiao-bin, PU Yuan-yuan, CHEN Jiao-guo, WANG Chen-xue, GUAN Hong-bo
Safety and Storage Evaluating Center, Hubei Institute of Aerospace Chemotechnology, Xiangfan Hubei 441003, China

Abstract: The study ways, characterization parameters and influence factors of deflagration to detonation transition are introduced.DDT tube, photoelectric cell, strain gauge and witness board are used to study the transition characteristics of the deflagration to detonation of NEPE propellant slurry in the mixing process. The relation curve between the predetonation column length of NEPE propellant slurry and the loading density in DDT tube exhibits a typical U shape. The deflagration to detonation transition can not occur for NEPE propellant slurry in the experimental condition, when the loading density of the propellant slurry is more than 95% of theoretical loading density. There is a better correlation between the fragmentation extent of DDT tube and the predetonation column length. The smaller the predetonation column length is, the severer the fragmentation extent of DDT tube.NEPE propellant slurry has the possibility of deflagration to detonation transition, because the vertical mixer is hermetic and the propellant slurry is inhomogeneous in the mixing process.

51. Study of Low Temperature Coefficient Mechanism of Polymer Deterred Propellants

HE Wei-dong1, DONG Chao-yang2
1. School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
2.Luzhou North Chemical Industrial Co.LTD, Luzhou Sichuan 646003, China

Abstract: In order to analyze the low temperature coefficient mechanism of single-base propellant deterred by poly(ethylene glycol dimethacrylate)(D1), the physicochemical properties, liner expansion coefficient and mechanical performance, of polymer D1 and single-base propellant at different temperatures are studied by dynamic mechanical analyzer and material tester. Combustion performances of deterred multi-perforation single-base propellants are studied by closed bomb test and interrupted-burning test.Results show that the linear expansion coefficients of D1 has large difference with that of single-base propellant. The exposed-perforation ratio of deterred single-base propellants at low temperature is larger than that at normal temperature. The low temperature coefficient effect of single-base propellant deterred by polyer D1 is the comprehensive results of two factors:(1) the differences of coefficient of expansion between the propellants and polymer D1 lead to some spaces between polymer D1 and propellants surface and increase burning surface area at low temperature;(2) the increase of burst ratio of deterred multi-perforation propellants at low temperature also reduces the temperature coefficient.

52. Kinetics of Lead Carbohydrazide Perchl Orate by Flash Pyrolysis

HU Xiao-chun~1, 2, ZHANG Tong-lai~1, ZHANG Jian-guo~1, QIAO Xiao-jing~1, YANG Li~1, SUN Yuan-hua~1
1. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
2. The 3rd Department, Institute of Chemical Defense, Beijing 102205, China

Abstract: The exothermic decomposition reaction kinetics of lead carbohydrazide perchlorate(PbCP) was determined by T-jump/FTIR spectroscopy at high temperatures following very rapid heating process. The time-to-exotherm(t_x) values evolved from the control voltage traces of the Pt filament during the flash pyrolysis yielded the kinetic parameters in the 300-340℃ range at 0.1MPa Ar atmosphere: E_a =70.68kJ•mol~-1, lnA =16.30. The activation energy determined was much smaller than that given previously by Kissinger and Ozawa-Doyle method, which also occurred with other energetic materials making these values qualitatively consistent.In addition, the decomposition kinetics of evolution of the major four individual gas products was resolved by the increase in specific absorbances, which might be essential for detailed combustion modeling of solid energetic materials.

53. The Factors Affecting Monoxide(CO)Concentration in Propellant Combustion Gas of a Gun-propelled Laser-guided Missile Propelling Charge

WANG Qiong-lin, JIANG Shu-jun, YU Bin, LIU Shao-wu, WANG Feng, CHEN Zhi-qun
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Some factors affecting CO concentration in combustion gas of a gun-propelled laser-guided missile propelling charge are investigated by means of closed-bomb-IR test used in lab scale investigation and on-line IR used in tank gun operation. Tests show that CO concentration is strongly related to the propellant and less strongly related to combustion pressure.Decreasing missile preserving temperature, adding small amount of oxidant into propellant, using oxidant bag in propelling charge all can decrease CO peak concentration in tank cabin effectively during firing. Turning on tank engine can speed up CO exhausting process greatly, but has no effect on CO peak concentration.Increasing cartridge ignitibility also can reduce breech flame phenomena. All these can be well explained by water gas reaction mechanism, oxygen balance and interior ballistic theory.

54. Gas Generation Rule about Tubular Gun Propellant with Two Different Burning Rate Layers

ZHANG Li-hua, HE Zeng-di, XIAO Zhong-liang
Institute of Chemical Engineering & Environment, North University of China, Taiyuan 030051, China

Abstract: To establish the Γ vs.Ψ expression, the gas generation rule about tubular gun propellant with two different burning rate layers was theoretically analyzed. Under the precondition of following the geometric combustion law, the equations describing Γ vs.Ψ relation of this kind of variable burning rate gun propellant were derived by using its initial geometric size, burning-rate ratio and density ratio of internal and external layer as the basic variables. The critical length-to-diameter ratio needed for elaborating the characteristics of progressive combustion of this gun propellant was obtained. The influences of inner diameter, length-to-diameter ratio and burning-rate ratio of this gun propellant on its gas generation rule were discussed through calculated Γ-Ψ curve examples. The calculated results showed that this tubular gun propellants with two layers can present progressive combustion in early stage while a step of Γ in intermediate or late stage when the initial geometric size and burning-rate ratio have proper values.

55. The Effect of Density in Composition B on Deflagration-Detonation-Transition Behavior

WEN Shang-gang~(1, 2), WANG Sheng-qiang~2, HUANG Wen-bin~1, ZHAO Feng~1, WANG Shi-ying~2, YAO Bao-xue~2
1.Institute of Fluid Physics, CAEP, Mianyang Sichuan 621900, China
2.Xi'an ModernChemistry Research Institute, Xi'an 710065, China

Abstract: The composition B applied widely in conventional weapons was chosen as the object of this research.By means of electrical pin and pressure gauge techniques, an experimental study was made to explore the different mechanisms at work in the deflagration-detonation-transition(DDT) of three kinds of 40/60-TNT/RDX-composition B with different density in the range of 1.597 to 1.681g/cm~3. The experimental results showed that there was a critical density for transition to detonation at certain confinement condition.Different densities resulted in different results, transition to detonation was more easier for low density explosive. Under strong confinement condition(steel tube with an inner diameter of 20mm and an outer diameter of 64mm and length 500mm), a DDT was obtained for the composition B with density of 1.597g/cm~3, and the inducement distance was 295 to 310mm.

56. Primary Study on Phenomena of Firelight Radiating from Explosion of Condensed Explosives

YI Jian-kun~1, YANG Zhi-xu~1, WU Teng-fang~1, HE Wu-yi~2, ZHAI Guo-feng~1
1. Engineering Institute of Engineer Corps, PLA University of Science & Technology, Nanjing210007, China
2.Guilin Institute of Air Force PLA, Guilin Guangxi 541003, China

Abstract: In order to understand the mechanism and factors of firelight radiating from explosion of condensed explosive, theoretical analyses on mechanism of radiation in each phase of explosion of condesed explosive were proceeded. The factors affecting the intensity of radiation based on analyses on experimental results in literature were studied. The phenomenon of firelight from explosion of sixteen kinds of condensed explosives were investigated with high speed photography. The results show that the process of radiation of firelight from explosion consists of two phases:detonation and afterburning. The detonation pressure, detonation temperature, detonation velocity and oxygen balance of condensed explosive have effect on the maximal intensity of radiation during explosion. The duration of firelight from explosion of condensed explosives is influenced by the oxygen balance and the mass of condensed explosive.

57. Application of Fast-Burning Energetic Compound ACP in HTPB Composite Propellants

RAN Xiu-lun~1, YANG Rong-jie~1, WANG Guo-qiang~2
1. College of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China
2.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effects of fast-burning energetic compound ACP with various contents in propellants on the combustion properties of low-burning rate, medium-burning rate, high-burning rate HTPB propellants were investigated by Crawford test and firing test of neutral burning Ф64mm motor. The results showed that the ACP made the burning rate of above-mentioned three kinds of HTPB/AP/Al propellants, and the pressure exponents of the propellants in the pressure range of 6.86-15MPa increase obviously.For instances, 5% ACP in propellant samples made the burning rate of above three propellants at 15MPa enhance by 11.3%, 82.9%, (67.8%), respectively. The firing tests of neutral burning Ф64mm motors loaded with HTPB/AP/Al propellant grain containing ACP showed stable chamber pressure-time histories. The primary evidence of non-parallel layer combustion in the motors by the fast-burning energetic compound ACP was obtained.

58. Test Method of Combustion Remains of Gun Propellant

WANG Qiong-lin, LIU Shao-wu, ZHANG Yuan-bo, ZHENG Shuang
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Characteristics of gun propellant combustion remains and their negative effects on interior and exterior ballistics have been studied, suggesting that gun propellant combustion remains can be sorted into three categories, one adhesive remains, one floating remains and another sinkable remains, and the front two remains are mostly harmful.Nitrogen-bomb test, a new method, is used to determine the amount of adhesive remains and evaluate the feasibility of the method.Fume-box tests, nitrogen-bomb tests and TG tests of some different gun propellants are conducted and results obtained show that nitrogen-bomb test can clearly show the difference of adhesive remains of different gun propellants.Floating remains are measured by Fume-box test. Tests reveal that different gun propellant has dramatically different adhesive remains, more adhesive remains usually accompany with more floating remains.

59. Combustion Properties of a Glued Consolidation Gun Propellant

MA Zhong-liang, XIA Ping, HE Zeng-di, XIAO Zhong-liang
Department of Chemistry and Environment, North China Institute of Technology, Taiyuan 030051, China

Abstract: The variable-burning rate gun propellant with glue and consolidation was manufactured with the grains of the variable-burning rate gun propellant as the base propellant and slightly managed with energetic glue to surface and firmly pressed. This charge has resolved the problem of progressive combustion of consolidation charge. The law of burning gas release of high charge density gun propellant was effectively controlled by combining the high charge density and progressive combustion performance of the variable-burning rate gun propellant. The combustion performance of base propellant and the variable-burning rate gun propellant with glue and consolidation were analyzed comparatively by the p-t and L-B curves from traditional closed bomb test. The results indicate that the variable-burning rate gun propellants with glue and consolidation kept high progressive burning of the variable-burning rate gun propellant and has high charge density and burning reappearance.

60. Function of Carbon Materials Used in Solid Propellants and Their Action Mechanism

WANG Han, ZHAO Feng-qi, LI Shang-wen, GAO Hong-xu
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The function in catalyzing combustion, action mechanism and action rules of carbon black, C_(60), fullerene soot, carbon fiber and carbon nanotube in solid propellants are summarized.It is found that the carbon black and C_(60) in double base(DB)or composite modified double base(CMDB) propellant can enrich catalyst, prevent catalysts from conglomerating and make double base systematic propellant produce plateau or mesa effect, the pressure exponent of double base systematic propellant reduce and the burning rate at low pressure of double base systematic propellant enhance evidently. The carbon fiber improves the conduction of heat exchange, increases intensity of propellant, enhances the burning rate of propellant and prevents propellant from cracking. The carbon fiber and carbon nanotube in propellant promote the decomposition of energetic material and enhance the burning rate of composite propellant. The development direction of the carbon materials used in solid propellants is prospected.

61. A Non-lead Catalyzed Nitramine Modified Double Base Propellant with Low Burning Rate and Low Flame Temperature

WANG Feng~1, QIN Neng~2, HE Hai-min~2, SUN Zhi-gang~2
1.Military Office, Xi'an North Huian Chemical Industry Lt. Co., Xi'an 710302, China
2.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: To decrease the burning rate and flame temperature of low flame temperature and low buring rate double base propellant, an energetic additive(PQ, a nitramine product) was added to a CMDB propellant containing HMX. The effect of the substitution of composite energetic additives composed of PQ and HMX for NC and NG partly on the burning rate and flame temperature of the propellant was studied, and the combustion performance of the propellant was adjusted using general Pb-Cu catalysts and non-lead salt catalysts. The results revealed that the PQ-HMX composite energetic additives are able to efficiently decrease the theoretical flame temperature to lower than 1200K and the burning rate was lower than 2.5mm/s at 10MPa and 20℃. Comparing with the use of general Pb-Cu catalysts, non-lead salt catalysts had higher catalyzing efficiency. The propellant containing non-lead salt catalysts showed better combustion performance, the pressure exponent reached as low as 0.16 in the range of 3-7MPa and appeared a plateau combustion phenomenon. The decrease of the burning rate and flame temperature by adding energetic additive PQ is due to the reduction of energy level of the propellant and the decrease of the chemical reaction rate by the endothermic melting of PQ.

62. The Influence of Agglomerated Boron on Burning Rate of Fuel-rich Solid Propellant

PANG Wei-qiang, ZHANG Jiao-qiang, HU Song-qi, DANG Jian-bo, GUO Ji-ying
Northwesten Polytechnical University, Xi'an 710072, China

Abstract: The agglomerated boron, which has good roundness and particle size of 0.105～0.19mm, has been prepared through a dry process, and the fuel-rich propellant sample which contain 32% of agglomerated boron and with the heat value 32MJ/kg has been successfully prepared. The burning rate and pressure index of propellant samples, with different AP gradation and Mg/Al(particle size) combination and agglomerated boron with different particle size, has been determined by strand burner method.It is found that the processing of fuel-rich solid propellant become less difficult when the agglomerated boron is introduced for replacing ordinary boron powder. That would make it realized to increase the content of boron, fine AP and other solid ingredients in composition so as to improve the heat value and combustion characteristics of propellant mentioned above. Especially, increasing the content of fine AP in composition has led to the significant enhancement of burning rate and pressure index of propellant samples, but the effects of particle size of Mg/Al and agglomerated boron are rather minor.

63. Catalysis of Bismuth 2, 4-Dihydroxylbenzoate in Combustion of Double-base Propellant

SONG Xiu-duo, ZHAO Feng-qi, XU Si-yu, GAO Hong-xu, GAO Yin
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: In order to evaluate the efficiency of bismuth 2, 4-dihydroxylbenzoate(β-Bi) on catalyzing burning of propellant and search for its effect mechanism, the sample of propellant containing β-Bi is prepared by extrusion technology, and the catalytic performance of β-Bi in the combustion of double-base propellant was investigated. The results show that β-Bi possesses good catalytic effect on combustion of double-base propellant and an excellent ability to enhance burning rate and reduce pressure exponent.When β-Bi together with a little carbon black(CB) and copper salt is used, the catalytic effect is better. The thermal decomposition mechanism of β-Bi was investigated by the simultaneous device of the solid reaction cell in situ/ RSFT-IR, discovering that the active component in the catalytic combustion process of propellant was Bi_2O_3.

64. Improvement of Burning Rate for Solid Propellants by ACP

WANG Feng~1, WANG Guo-qiang~2, TENG Xue-feng~2, ZHONG Lei~2, LIAO Lin-quan~2, RAN Xiu-lun~3
1.Military Office, Xi'an North Huian Chemical Industrial Lt. Co., Xi'an 710302, China
2.Xi'an Modern Chemistry Research Institute, Xi'an 710065, China;3.Beijing Institue of Technology, Beijing 100081, China

Abstract: Extraordinary and outstanding effect of improving the burning rate of modified double-base propellant, AP based composite propellant and N-15D propellant was achieved with fast-burning energetic material ACP. The burning rates of propellants were all substantially improved but the pressure exponent was not changed basically by incorporating ACP with different particle size and content into HMX-and RDX-based modified double-base propellants. The burning rate was greatly increased by incorporating ACP into AP based composite propellant and the pressure exponent was superior to 0.45 at 7～15MPa.It was successfully tested on the Φ64mm motor and p-t curve was obtained. The burning rate of base formulation was quite low when incorporating ACP into N-15D propellant, but the burning rate was still improved and the pressure exponent was increased slightly. The increments of the burning rate were 40.62% for HMX-based modified double propellant, 38.00% for RDX-based modified double propellant, 37.35% for AP based composite propellant and 9.90% for N-15D propellant.

65. Low Temperature Sensitivity of Variable-burning Rate Gun Propellant

HE Zeng-di, LIU You-ping, MA Zhong-liang, Lü Bing-feng, XIAO Zhong-liang
Department of Chemical Engineering, North University of China, Taiyuan 030051, China

Abstract: By changing thickness of the crazes with temperature, the burning area of the propellant is changed. A compensating system is founded in two-layered variable-burning rate propellant and low temperature coefficient of the propellant is realized. The craze and thickness of craze changing with temperature were observed by means of SEM;The combustion character of two layered variable-burning rate propellant at high, low and normal temperature was obtained by the closed bomb test. The interior ballistic performance on 30mm gun to observe temperature coefficient was analyzed. The results indicate that using the thickness of craze changing with temperature to change the burning area of the propellant can change the rate of gas production of propelling charge. The closed bomb test shows that the combustion performance is about the same at different temperatures. The interior ballistics performance shows that the varibable-buring rate propellant has low temperature coefficient.

66. Combustion Property of High Energy and High Strength Propellant

HUANG Zhen-ya, WANG Ze-shan, HE Wei-dong, XU Wan-yu
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: In order to search the combustion performance of a new propellant with polyether polyurethane binder plastized by mixed nitrate ester, the combustion characteristic of the JMZ propellant in the range of different pressure was researched by closed bomb normal test and high pressure test. The test results showed that burning rate pressure exponent values of the JMZ propellant are large at low pressure, as those of RDX nitramine propellants, but the burning rate pressure exponent values gradually diminish along with increase of pressure and are equivalent to those of conventional propellants at high pressure. There are no obvious turning phenomena in course of the change of burning rate pressure exponent values.In addition, according to the test results, the JMZ propellant revealed a good burning progressive in initial stage which should be beneficial for barrel weapon.

67. Combustion Property of Oblate Propellant with Micropores in Air

LIN Xiang-yang, CHENG Xiang-qian, PAN Ren-ming, YIN Ji-gang
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: In order to study the combustion property of oblate propellant with micropores prepared by chemical foamed process, the apparent mass burning rate of the propellant is measured by strand burner method in air at normal pressure. Experimental results show that the bulk density, grain size, test temperature and the loading condition have obvious effects on the mass burning rate of the oblate propellant with micropores. The mass burning rate of single base micropores propellant increases with decreases of the bulk density.It also increases with the rise of load diameter and the particle size. Comparing with normal propellant, test temperature has more effects on the mass burning rate of single base oblate propellant with micropores.When test temperature increases from 288K to 332K, the mass burning rate of single base oblate propellant with micropores increases over 4.5 times. The materials of tube for loading particles and the load height have less effect on the apparent mass burning rate.

68. Temperature Response of Aluminum Particle Heated by Thermal Effects of Explosive Detonation

LUO Ai-min, ZHANG Qi, BAI Chun-hua, LI Jian-ping
Disasters, Beijing Institute of Technology, Beijing 100081, China

Abstract: A analysing system of high speed movement is used to record detonation products expansion process of Nitromethane(NM). The temperature response of aluminum particles is calculated by using thermal penetration theory under thermal effects of NM detonation. The results show that the thermal effect of NM detonation on aluminum particles is more intensive in expansion phase than that in region of NM detonation, whereas this effect on aluminum particles in detonation zone is neglected. Smaller aluminum particle in NM detonation region can be heated to its ignition temperature promptly, impling that aluminum oxidation reaction becomes possible in region of NM detonation.

69. Reaction Mechanism of Metallized Explosive with Composite Metals Powder

HUANG Ya-feng, WANG Xiao-feng
Xi'an Modern Chemistry Research Institute, Xi'an710065, China

Abstract: The reaction mechanism of Ti-Ni metallized explosive is investigated by detonation heat comparison between calculation and experiment result and X-ray experimentation of solid reaction products. The results of X-ray experiments show that there are oxide and alloy in the detonation products. The content of titanium which is oxidized into oxide is 57.0%, which is more than that of titanium turning into alloy. So there is not only alloy reaction but also oxidization reaction in the reaction of metallized explosive containing Ti-Ni metal powder, and oxidization reaction is faster than alloy reaction, which is in line with chemistry kinetics.

70. The Low Temperature-sensitive Coefficient Charge of Flat Ball Gun Propellant

ZHAO Qi-lin, HUANG Shun-you, LI Chun-zhi
Luzhou North Chemical Industries Co., Ltd, Luzhou646003, China

Abstract: A low temperature-sensitivity charge, which was composed of loose flat-ball gun propellants and dense flat-ball gun propellants, was designed. The temperature-sensitivity of designed charge was controlled by adjusting the proportion of loose propellant. The burning properties, chamber pressure wave and physical stability of the charge at different temperatures were characterized by close bomb test and 30 mm gun shooting test. The results show that the designed charge has relatively low temperature-sensitivity, stable chamber burning properties, excellent physical stability and shooting security.

71. Adjustment on the Burning Behaviors of the Propellant Containing Diazidopenane

WEI Xue-tao, Qing Hui, CUI Peng-teng, LIU Yi, YANG Jian-xing
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Based on comparision and analysis of the adjustment technical paths of the combustion performance of propellant, the principle and method of adjusting the combustion performance of DIANP propellant with high content of plasticizer is proposed. The deterrent coated material suitable for DIANP propellant is determined, it is composed of DIANP propellant and a deterrent B. The combustion properties of deterrent coated DIANP propellant are tested with the closed bomb. The experiment results show that using deterrent coating technique could reduce the initial pressure rate of DIANP propellant, and obtain the effect of progressive combustion; the coated thickness is the most important factor of the deterrent- coated propellant for adjusting combustion performance.

72. Presentational Regulations of Combustion in Propellant of Gun-Boosted Missile

WU Xiao-qing, XIAO Zhong-liang
Department of Chemical Engineering, North China Institute of Technology, Taiyuan030051, China

Abstract: The launching characterization of gun-boosted missile was discussed, and its characterization in propellant is that the combustion pressure is between solid propellants and conventional solid propellants. The combustion properties of the propellant of gun-boosted missile in the process of launching were tested and assessed in the closed combustion bomb with the pressure range below 100 MPa. The results show that it has different characteristics compared with conventional propellants. All of these will have practical significance for the study of new type propellant of gun-boosted missile.

73. Theoretical Research of Influence of Chemical Components on Combustion Property of Double Base Plateau Propellants

WANG Yi~1, SONG Hong-chang~2, BAI Hua-ping~2, KANG Jian-cheng~3
1. The 705 Research Institute of China Shipbuilding Industry Corporation, Xi'an 710065, China
2. Nanjing University of Science and Technology, Nanjing 210094, China
3. The Military Affairs Department of No. Taiyuan Xing'an Factory of Chemical Material, Taiyuan 030008, China

Abstract: The influence of main chemical components of double base plateau propellant on its combustion property was investigated by theoretical computation, which was based on one-dimensional gaseous phase reaction flow model. The computation results were not only in agreement with domestic and international practical experience, but also could explain the chemical essence of propellant burning process. So through optimizing propellant formula, the results might be used to adjust the burning rate and pressure exponent of double base plateau propellants.

74. Inhibition of Very High Burning Rate Propellant

LI Xiao-dong, YANG Rong-jie, LI Jian-min
School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China

Abstract: A novel propellant, which was of porous structure and had very high burning rate (above 1 000 mm/s), was prepared. Its inhibitor is very important in studying the application of very high burning-rate propellant. The propellant grains with size Φ 25×25 mm were inhibited using polyvinyl chloride (PVC) as inner layer and cellulose acetate added flake asbestos as outer layer. The experiment of determining the thickness of coating layer, termination burning and indirect proof were studied. Results show that the convection burning of VHBR propellant is stable, no flame-leak. Its burning rate is above 1 000 mm/s by using this way.

75. Combustion Property Character of Variable-burning Rate Gun Propellant

HE Zeng-di , LIU You-ping, MA Zhong-liang, Lü Bing-feng, XIAO Zhong-liang
Dept. of Chemical Engineering , North China Institute of Technology , Taiyuan030051, China

Abstract: The principle and realizable approach of variable-burning rate propellant, the burning rate of inner layer is higher than that of the outer layer are introduced. The combustion character of two layered variable-burning rate propellant in closed bomb test is analyzed and the interior ballistic performance on 30mm gun is construced. Contrast with single base gun propellant with polymer coating layer, the two-layered variable-burning rate propellant has good properties of progressive combustion and low temperature coefficient.

76. Establishment of Burning Rate Models of Smokeless Modified Double-base Propellant Containing Fast Burning Energetic Substance

LIAO Lin-quan, QIN Guang-ming, LI Xiao-jiang
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Four mathematical models describing the combustion of smokeless modified double-base propellant, which contain fast burning energetic substance with different shapes (cube, globular, cuboid, and slice), are established. The mathematical equations of burning rate and the available size of fast burning energetic substance substances in the direction of combustion are deduced. With the help of the established mathematical model, the burning rates of propellants containing 5% and 7% ACP are calculated under different pressures. The results show that the calculated values of burning rates are in good agreement with the experimental ones.

77. Ignition and Combustion Behavior of a Type of LOVA Solid Propellant

YANG Chun-xia, ZHAO Bao-chang, LI Bao-ming
Ballistic Lab, Nanjing University of Science and Technology, Nanjing210094, China

Abstract: To study the ignition and combustion behavior of a type of LOVA propellant based on RDX, the closed vessel experiments are accomplished. Then the different patterns of the obtained P-t curve and dP/dt-P/P(max) curves are given and analyzed, and the interaction mechanism plasma and LOVA propellant is discussed for the further research on the configuration of propelling charge and enhanced combustion effect in application to ETC firing.

78. Burning Properties of a New Kind of High-burning Rate Propellant

MA Yu-ying, GUO Xiao-de, LIU Yun-zhi
Shanxi xing′an Factory of Chemical Materials. Taiyuan030008, China

Abstract: This article introduces the porons grain structure and combustion characteristics of a novel high burning-rate propellant.Base on motor test results, it is found that the propellant exhibit three type of combustion manners at different motor loading parameters. The combustion manners include parallel layer burning, limited convection burning and convection burning.

79. Ignition and Combustion Behaviors of LOVA Gun Propellant

ZHANG Yu-cheng, YANG Li-xia, JIANG Shu-jun
Xi'an Modern Chemistry Research Institute, Xi'an710065, China

Abstract: Two kinds of LOVA gun propellants with different binders were prepared. They are L15A (RDX76%, NC4%, DOP8%) and L13A (RDX76%, NC4%, CAB12%, ATEC8%) respectively. The ignition and combustion behaviors were investigated with a closed bomb and a simulator of ignition and combustion. The results indicate that the LOVA gun propellants are difficult to be ignited, however, its ignition behavior can be improved by adding AP into the igniter. The LOVA gun propellants have the characteristic of lower coefficient and higher exponent to its exponential formula of burning rate versus pressure. The rule of gas generation and burning behavior in the initial stage of the two LOVA samples were studied by the closed bomb tests at the same ignition condition. It is found that there is a rapid
increasing of gas generation rate for the LOVA propellant with energetic binder. It shows that the LOVA propellant with energetic binder has a better ignition ability compared to the LOVA propellant with inert binder.

80. Study on Combustion Mechanism of Fuel-rich Propellant Holding Boron Coated with AP

WANG Ying-hong, LI Bao-xuan, HU Song-qi, LI Jin-xian
College of Astronautics, Northwestern Polytechnic University, Xi'an710072, China

Abstract: The combustion wave temperature profiles and flame structures of fuel-rich propellant containing boron are measured by using W-Re micro-thermal couple and flame photo technique. The surface appearance and element distribution of extinguished samples are analyzed by JMS-5800SEM. The heat which releases in condensed-phase is obtained by integrating the DSC curve. The difference of the combustion characteristic between two propellants whose contain boron coated with and without AP is compared by measuring the heat of explosive and burning rate of the propellants. The results show that when the formulations are invariable, which coatins boron coated with AP, the adiabatic flame temperature of explosion and the burning rate in lower pressure are increased. Meanwhile, the combustion course of the propellant was confirmed preliminary.

81. Current Progress of Flame Retarded Polyurethane Materials Containing Phosphorus and Halogen Flame Retardants

CHANG Hai~(1, 2), WANG Ji-gui~2, GAN Xiao-xian~2
1. Northwest Polytechnic University, Xi'an710072, China
2. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: This paper introduces the current progress of flame retarded polyurethane materials containing phosphorus and halogen flame retardants . The main works are now developing new additive flame retardants, reactive flame retardants of organic phosphnate and flame retarded binders for flame retarded polyurethane materials. This paper also suggests that the future works should focus on improving comprehensive properties of flame retarded polyurethane materials and going deep into study flame retarded mechanism.

82. Investigation of Solid Explosives Initiation under Shock Waves

CHEN Lang~1, WU Jun-ying~1, FANG Qing~2, Ke Jia-shan~1, FENG Chang-gen~1
1. LAb prevention and control of explosion disasters, Beijing Institute of Technology, Beijing100081, China
2. LAB of shock waves and detonation physics research, Institute of Fluid Physics, CAEA, Mianyang 621900, China

Abstract: For investigating the characteristics of solid explosives initiated by shock waves, the Card Gap Test of JO-9195 explosive was carried out and recorded with high speed camera. The critical thickness of plexiglass clapboard to initiate the explosive was predicted. The shock initiation model of explosives was given. The numeicral simulations of explosive initiation were conducted. The pressure histories inside explosives under shock waves loading were calculated. The threshold pressure to initiate the explosive and the run distance of detonation were discussed.

83. Study of the Flame Retardant Mechanisms of Phosphorated Flame Retardants in Polyurethane Elastomer

SHI Ai-juan, WANG Ji-gui
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The flame retardant mechanisms of two phosphorated flame retardants P1~# and TCP in isocyanurate-modified polyurethane elastomer (IMPUE) were studied. By limiting oxygen index (LOI), TG-DTA, FTIR and X-ray spectrum. The results show that the flame retardant mechanisms of P1~# and TCP used for IMPUE are the gas phase, condensed phase and discontinuous heat exchange, of which gas phase mechanism and discontinuous heat exchange mechanism were predominant mechanism of P1~# to IMPUE. The condensed phase mechanism and discontinuous heat exchange mechanism were predominant mechanism of TCP to IMPUE.

84. Several Problems Inquired on CARS thermometry in Propellant Combustion

HAO Hai-xia, LI Chun-xi
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: A discussion is given that soot, C2 radical and laser intensity have an influence on CARS(Coherent anti-Stokes Raman Scattering )applied to propellant combustion, and temporal and spatial resolution is inquired into CARS thermometry precision in propellant flame. The discussion demonstrates that it is necessary to research that the propellant flame soot has an effect on CARS temperature and that the importance of realizing high temporal and spatial resolution are realized in propellant combustion.

85. The Soft-sensing Megtlier of the Inwall Temperature of Closed-bomb

HUANG Feng-liang~1, YU Yong-gang~2
1. Dept of Control Science and Engineering, Nanjing Normal University, Nanjing210042, China
2. College of Power Engineering, Nanjing University of Science and Technology, Nanjing210042, China

Abstract: Based on a soft-sensing model and its corresponding solution, and combined with an example, the inwall temperature of closed bomb has been studied with the soft-sensing method. The results show the inwall temperature of closed bomb can be measure with the given model and its solution. The obtained curve of the inwall temperature vs time before the peak value is smooth. It is very important for further study on the maximum temperature.

86. The Application of Surface Active Agent in Propellants

LIAO Xin, HUANG Zhen-ya, YANG Wen-bao, WANG Ze-shan
1. Nanjing University of Science and Technology, Nanjing210094, China
2. Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The combustion properties of LOVA propellant were studied through closed vessel. The results show that the particle geometry and grain size of nitramine influence the combustion property greatly. The nitramine treated by chemically re-crystallization was needle-like, the propellant made by this nitramine could produce stress centralization easily, and this nitramine was not good for improving its burning property. The nitramine treated by ball grind was cobblestone-like and efficient for combustion property. The larger of the nitramine grain size, the higher of the burning rate and the exponent. The combustion property of propellant could be improved by decreasing its grain size, but its burning rate index would become high when the grain size was smaller than a value. After treating the nitramine with surface-active agent, the combustion property of the propellant could be improved greatly.

87. Influence of the Surface Treating of Azidonitramine Propellants on Their Initial Combustion

YANG Li-xia, JIANG Shu-jun, LI Li, YANG Yan
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The characteristics of initial combustion in gun chamber concerning the surface treated azidonitramine propellants with desensitizing and coating were studied by means of experiments. The results show that the initial combustion performance of the surface treated is improved. The results also show the differences of influence between two kinds of surface treating on the initial combustion.

88. Study on the Clear-burning Gun Propellant

WANG Qiong-lin, LIU Shao-wu, TANG Hui-min
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Deterred-propellant often results in muzzle smoke. A new kind of clear-burning double base gun propellant contain polymer deterrent and new stabilizer is introduced. The propellant has low muzzle smoke, low maximum pressure, high muzzle velocity, low temperature sensitivity and excellent safe life. This improvement in interior ballistic performance is achieved by a combination of high oxygen-containing and diffusion-stable deterrent, slightly increased energy content and very progressive burning behavior.

89. Safety for High Energy Nitramine Propellant Used in High Pressure Gun

HUANG Zhen-ya, LIAO Xin
Nanjing University of Science and Technology, Nanjing210094, China

Abstract: The characteristics of pressure wave, adaptabilities of interior ballistic and dynamic burning alive in lower temperature of RGD7 propellant in high pressure gun have been studied and analyzed, by using the 30 mm high pressure simulated gun tests and comparing to the single base propellant. The results show that the characteristics of low burning rate in lower pressure make for improving the dynamic conditions in bore and putting up preferable adaptabilities of interior ballistic, so that RGD7 propellant has fine safe property used in gun. But its mechanics performance in lower temperature should be more improved by reason of higher dynamic burning alive in lower temperature.

90. Combustion Characteristics of Smokeless XLDB Propellant at Low and High Pressure

ZHANG wei, CHEN jin-nan, FAN hong-jie
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The combustion characteristics of smokeless XLDB propellant at different pressure were studied in detail by analysis of flame structure, combustion waves and SEM. It was showed that the model of combustion process of smokeless XLDB propellant is transferred from that of double-based propellant type to composite propellant type.

91. Combustion Property of NEPE Propellant

LIU Yun-fei, YAO Wei-shang, LI Xiao-meng, TAN Hui-min
Beijing Institute of Technology, Beijing100081, China

Abstract: NEPE high energetic solid propellant has been in prospect of application for its excellant comprehensive properties. The burning rate and pressure exponent were adjusted through adjusting the content and kind of oxidizer and the consumption of plasticizer. The burning rate was adjusted from 9.3 mm/s to 11.6 mm/s on 7.0 MPa. The pressure exponent was dropped from 0.61 to 0.54.

92. Energetic Lead or Copper Salts of Hydroxypyridines as Combustion Catalysts of RDX-CMDB Propellant

ZHAO Fengqi, CHEN Pei, LUO Yang, ZHANG Ruie, LI Shangwen
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effect of six kinds of energetic lead or copper salts of hydroxypyridines on the combustion properties of RDXCMDB propellant was investigated. It is discovered that the lead salts of hydroxypyridines containing nitro groups possess better catalytic effect and ability to reduce pressure exponent for the propellant, especially for lead salt of 2hydroxy3, 5dinitropyridine, which has the highest catalytic efficiency. The catalysis of the energetic copper salts of hydroxypyridines in the propellant is not obvious. The catalysis difference between lead salt 2hydroxy3, 5dinitropyridine and 4hydroxy3, 5dinitropyridine is due to their different thermal decomposition mechanism and different carbon content formed in the decomposition process.

93. Adjustment on the Combustion Performance of Low Flame Temperature and Low Burning Rate Double Base Propellant

QIN Neng1, 2 , WANG Liang2, WANG Ningfei1
1. Northwestern Polytechnical University, Xi'an710072, China
2. Xi'an Modern Chemical Research Institute, Xi'an710065, China

Abstract: To adjust the combustion performances of low flame temperature and low burning rate propellants, some catalysts, shch as lead salts, copper salts, carbon black and assistant plasticizer were appended into four low buring rate formulations, whose theoretical flame temperature ranged from 900K to 1700 K, and the function of the catalysts and their additive amount were tested. The results show that those usual catalysts can also work upon low flame temperature and low burning rate DB propellants. The variety of catalysts have different effects on burning rate and pressure exponent, and the combined catalysts can improve the combustion performance obviously. Besides, assistant plasticizer can also affect the combustion performance.

94. Theoretic Analysis on Pressure Sensitivity of Ultra High Burning Rate Propellant

LI Xiaodong, YANG Rongjie, LI Jianmin
Beijing Institute of Technololgy, Beijing100081, China

Abstract: Pressure sensitivity of ultra high burning rate propellant (UHBRP)was analyzed theoretically. A technological method of reducing the pressure sensitivity of UHBRP was referred. By this mothed, the densities of UHBRP pellets increase gradually from one end to another, then pressure sensitivity will be reduced greatly, the pressure exponent will be reduced to zero theoretically.

95. The Influence of Different Damages of CCCF Composite Propellant Charge on the DDT Behavior

LEI Weiguo, WU Jieling
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Damaged samples of HTPB/AP CCCF composite propellant charge was prepared by four kinds of methods which may simulate the different damage states of high energy gas fracturing application. Their influences on the combustion stability and DDT behaviors were investigated through hermetic bomb test and DDT tube test. It is concluded that DDT would not occur in these damaged charges under nonconfined conditions, but might occur in the oil well.

96. Study on Combustion Property of NEPE Propellant with Low Aluminum Content

LI Xiaomeng, LIU Yunfei, YAO Weishang, TAN Huimin
Beijing Institute of Technology, Beijing100081, China

Abstract: The combustion properties of NEPE propellant with 8% aluminum content were studied. It was observed that increasing the ratio of NG/DEGDN, decreasing the particle size of AP, and increasing contents of fine particle AP are effective measures to increase the burning rates of the propellant. Simultaneously, decreasing the particle size of HMX can reduce it's burning rate and pressure exponent. PbCO3 synthesized by ourselves can reduce the pressure exponent more than the bought one.

97. Study on the Combustion Stability of Desensitized Propellants

LI Li, ZHAO Baochang, XU Bin
Nanjing Normal University, Nanjing210097, China

Abstract: The combustion stability of three main types of gun propellants (single based propellant, double based propellant and nitramine propellant), which are desensitized with two different methods, is analyzed and evaluated. The effect of the two desensitized methods on combustion stability of the propellants is concluded. It is shown that the burning rate of the propellants increase through both of the two desensitized methods, but the unstability of combustion and the burning ratepressure exponent respectively increase also.

98. CARS Diagnostics for Combustion Flame Temperature of Double-base Propellant

LI Chunxi, ZHAO Ming, ZHANG Ruie, YUAN Chao, ZHAO Fengqi
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The combustion flame CARS spectra of the doublebase propellant and its flame temperature values have been obtained. The results show that the temperature measured by CARS spectroscopy is in agreement with values calculated by thermodynamics. The temperature change observed by continuously collecting the CARS spectra indicates that CARS technology can be used for realtime diagnostics of the flame temperature during the propellant combustion.

99. Experimental Study on Ignition and Flame Spreading of Modular Charge

YU Bin
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: This thesis presents experimental studies and theory analysis technology of ignition and flame spreading, as well as interior ballistic cycle in the gun with modular charges. The ignition and its flame spreading test system of the modular charges in the natural environment is built up, a number of ignition and its propagation methods are simulated, the characteristic parameters of the system in the natural environment are obtained.

100. The Closed Vessel Study of Low Temperature Nitroamine Propellant Combustion Properties

SHI Xian yang, WANG Ze shan
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The combustion properties of low temperature sensitivity coated (LTSC) nitroamine propellant had been studied using granule powder as concussion gas source in closed vessel. Compared the burning properties of coated nitroamine propellant at different temperatures and of different coated layer thickness. This is one of the basic tests for inspecting the LTSC effect of coated propellant.

101. Mechanism Analysis of the Influense of Al Shape and Size on the Detonation Properties of Aluminized Explosives

MIAO Qin shu, XU Geng guang, WANG Ting zeng
Beijing Institute of Technology , Beijing 100081, China

Abstract: The mechanism of the influence of the shape and particle size of alumiuium on the detonation properties of aluminized explosives is explained by means of the secondary reaction theory and the heat dilution theory. It is indicated that the fundamental factor is the specific surface area changed with different shape and paricle size of aluminium. It has also been pointed out that changing the particle size of Aluminium is a good way to optimize the properties of aluminized explosives.

102. Progress In Investigation of condensed Explosives Initiated by Low Amplitude Shock (XDT)

KE Jia shan, CHEN Lang , FENG Chang gen
School of Mechano Electronics Engineering, Beijing Institute of Technology, Beijing 100081, China

Abstract: This paper presents the XDT events of condensed explosive by low amplitude shock, and recommends the methods of experiments and numerical simulation for the XDT investigations . The developing trend for XDT investigation is forecasted.

103. Study on Curing Catalysis of Combustion Catalyst for EMCDB Propellant

LIU Chun, LI Xiao jiang, CAI Bing yuan, AN Fang yan
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The experiment, applied to study the curing catalysis of combustion catalysis for polyurethane EMCDB propellant, was designed, the catalytic activity of eight Pb salts and four Cu salts was compared, the Pb salts and Cu-salts, which could be used as combustion catalyst ingredient of EMCDB propellant, were selected. Experimental results showed that some Pb salts had stronger catalytic activity to the cross linking reaction, almost all Cu salts and carbon black had no catalytic activity, only these Pb salts, which had weaker catalytic activity, could be used as the combustion catalyst ingredient of EMCDB propellant.

104. Critical Pressure of Smokeless Propellant

CHEN Guang xing, QIANG Jie bing, YU Hong jian
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Critical pressure concept of solid propellant was introduced. The condition of maintainting RDX CMDB propellant steady burning, study of lowering critical pressure of RDX CMDB propellant and relative experiment was disscused.

105. Research in Solid Fuel-Rich Propellant

ZHANG Wei, ZHU Hui, FANG Ding you
National University of Defense Technology, Changsha 410073, China

Abstract: It was reviewed that the development in solid fuel rich propellant abroad and mainland. The composition, combustion characteristics and its modification of the various fuel rich propellant, the hydrocarbon propellant, the magnesium propellant and the boron propellant, were demonstrated.

106. Deflagration to Detonation Transition Behavior of Explosive JOB-9003

HUANG Yi min, FENG Chang gen, LONG Xin ping
Department of Engineering Safety, Beijing Institute of Technology, Beijing 100081, China

Abstract: The experiments of the deflagration to detonation transition of granular HMX and JOB 9003 explosives were carried out. The effects of the composition, density and confinement of explosives on the DDT process were studied. The principles of explosives DDT were analyzed. The experimental results illustrate the compositions and the charge conditions of explosives have influences on DDT behavior. The granular HMX explosives are easy to happen DDT, but the pressed JOB 9003 explosives composed by HMX chiefly are not.

107. Study on the design method of grain binding high burning rate propellant

SHA Heng, LI Feng-sheng, SONG Hong-chang, CHEN Su-lin
China North Chemical Industrial Corporation, Beijing 100089, China
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: The processing technique of grain binding high burning rate propellant (GBHRP) was introduced. The burning rates of both small grainy propellants and fast burning binders were calculated by means of the burning rate-calculated ch aracteristic chemical group method of propellant. The burning rate-designed met hod of grain binding high burning rate propellant was proposed.

108. A New Method to Improve the Burning Performance of Oblate Spherical Propellant

XONG Li-bin, YING San-jiu, LUO Fu-sheng
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: A method to improve the burning performances of single-base oblate spherical po wder is developed. Tests show that adding fine KNO 3 grains and deterrent to pr opellant powder can improve its inner burning area and affect its burning rate e fficiently. Thus a kind of progressing burning single-base oblate spherical is available.

109. Study on the Combustion Properties of XLDB Propellant

LU Dian-lin, FAN Xue-zhong, SUN Yu-kun
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The effects of all factors, such as different types of catalyst, RDX, NG etc., o n the combustion properties of XLDB propellant were thoroughly studied. The spec ific impulse of the propellant determined by Φ64mm motor is also reported. It w as found that the effects of these factors on the combustion properties of XLDB propellant is obvious.

110. Study on Low Burning Rate NEPE Propellant

LI Xiao meng, LIU Yun fei, YAO Wei shang, TAN Hui min
Beijing Institute of Technology, Beijing 100081, China

Abstract: A low burning rate NEPE propellant were investigated by means of adding some burning rate inhibitors and adjusting its composition. The compatibility of additives with nitrite ester, combustion properties of the propellant and the standard specific pulse of Φ40 rocket motor were measured. It was observed that the burning rate of the propellant could be depressed by more bigger particle diameter AP , low ratio of NG/DEGDN, less AP content and presence of burning rate inhibitors. The burning rate under 4.0MPa could be 4.7mm/s, and standard specific pulse was 2239.3N•s/kg without additives.

111. The Experimental Studies of the Augmentation Combustion of Propellants with Plasmas

XIE Yu shu, YUAN Ya xiong, ZHANG Xiao bing
Nanjing University of Sciende and Technology, Nanjing 210094, China

Abstract: Plasmas can alter ballistics process through control and augmentation combustion of the propellants in ETC technology, To date, the mechanisms have not been certain how plasma could modify the propellant gas generation. Many scholars have tried to explain the plasma propellant interaction mechanisms by a series of test. This paper mainly introduced the experimental studies on burn rates of the propellant with plasma abroad, including experimental equipments, methods and results.

112. Effect of Azide Nitrate Ester on Combustion Behaviour of Nitramine Modified Double Base Propellant

WANG Jin, LI Shu fen
University of Science and Technology of China, Hefei 230026, China

Abstract: The influence of azide nitrate ester PDADN [1, 3 propanediol, 2, 2 bis(azidomethyl), dinitrate(ester)] on combustion property of nitramine modified double base propellant has been studied. The results show that PDADN can increase burning rate and energy of nitramine modified double base propellant.

113. Study on the Temperature Determination Technique for Ignition and Combustion of Propellants

YU Bin, DU Cheng zhong
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The experiments for temperature of ignition and combustion of two propellants were done by six channel instantaneous optical pyrometer, the temperatures of ignition and combustion of two propellants were determined at different pressure and the results of experiments were analyzed, which may be used to the further studies for temperature of ignition and combustion of propellants.

114. Experimental Research on the Ignition Process of Energetic Droplet

YU Yong gang, JIN Zhi ming, LIU Feng, WU Dong lou
Nanjing University of Science and Technology, Nanjing 210094, China

Abstract: Optical computerized tomography and multimedia technique of computer were used to visualize and analyze the ignition process of energetic droplet LP1846 under atmospheric pressure. Time series interference graphs of the droplet from heat decomposition to combustion were showed dynamically. The ignition temperature of the drolpet was also calculated. Experimental results show that the ignition and combustion properties of the energetic droplet can be studied with optical computerized tomography.

115. Research on Lowering the Flame Temperature of Aerosol Generating Agent Using Additives

QIAO Hai tao, YANG Rong jie, LI Xiao dong
Beijing Institute of Technology, Beijing 100081, China

Abstract: The influence of two kinds of additives on the flame temperature of EBM extinguishing agent has been studied. The flame temperature can be obviously lowered by the additives. It is found that the combination of two kinds of additives is more effective for lowering the flame temperature of the aerosol generating agent.

116. Study of Combustion Property of HNIW Monopropellant

AN Hong mei, LIU Yun fei, LI Xiao meng
Beijing Institute of Technology, Beijing 100081, China

Abstract: The combustion property of HNIW monopropellant was studied by adding some additives. The results of experiments indicate that the decomposition products of HNIW affected the burning behaviors of HNIW monopropellant. The burning rate of HNIW monopropellant is decreased through adding the products of decomposition of HNIW. The used catalysts in the experiment have catalyzed the combustion property of HNIW monopropellant.

117. Study on Combustion Mechanism of NEPE Propellant

WANG Ying, SUN Zhi hua, ZHAO Feng qi, LI Shang wen, YUAN Chao
Xi'an Modem Chemistry Research Institut, Xi'an 710065, China

Abstract: The combustion wave temperature profiles and the flame structures of NEPE propellant samples are measured by using W Re micro thermalcouple and flame photo techmique. The influence of major component of propellant (such as HMX, AP, Al)on the combustion properties is researched; Meanuhile the surface appearance and element distribution of extinguished samples are analyzed by JMS 5800 SEM. The combustion process of NEPE propellant is suggested by synthetic analysis.

118. Study on Catalytic Combustion of HNIW Monopropellant by Metal Oxide

AN Hong mei, LIU Yun fei, LI Yu ping, YANG Rong jie, TAN Hui min
Beijing Instiute of Technology, Beijing 100081, China

Abstract: The catalytic combustion of Hexanitrohexazaisowurtzitane was studied in this paper. The result of experiments indicates that the burning rate of HNIW monopropellant is about two times of that of HMX monopropellant. The burning rate of HNIW monopropellant increases with pressure increasing. The pressure exponent of burning rate is 0.846. The burning rate of HNIW monopropellant can be changed through adding metal oxide but the pressure exponent of burning rate is not changed by metal oxide.

119. Study on Burning Rate Regulating by Combustion Stabilizer

ZHANG Xiao hong, ZHANG Rei er, WANG Bai cheng
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: On the basis of the research of different combustion stabilizers and common stabilizer Al 2O 3 on the burning rate, further research has been carried out on the possibility using different size of those stabilizers to regulate the burning rate of the propellant.

120. Combustion Properties of Insensitive Nitrocellulose Based Propellant Containing Potassium Compounds as Flash Suppressors

ZHAO Feng qi, CHEN Pei, YANG Dong, LI Shang wen
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: The combustion properties of insensitive nitrocellulose based propellant containing potassium compounds as flash suppressors investigated in this paper. The results indicate that the addition of K 3AlF 6 badly destroys the plateau burning effect of insensitive propellant, while flash suppressor KD almost do not destroys the platonisation. The burning rates and the plateau range of the propellant containing KD can be adjusted by means of the change of composite catalysts. After 1, 2, 4 butanetriol trinitrate (BTTN) is substituted for trimethylolethane trinitrate (TMETN), the burning rates of the propellant increases apparently and the plateau effect is maintained. Nitroguanidine (NGu) enables the propellant to appear burning rate jump between 8 and 9 MPa and to produce plateau burning effect under higher pressure.

121. Study on the Traveling Charge Technique with Steady Deflagration

TAN Hui min, LUO Yun jun, DUO Ying quan
Beijing Institute of Technology, Beijing 100081, China

Abstract: In this paper, the steady deflagration process was delt with, the new concept which use the steady deflagration as propelling energy source of traveling charge was presented. The classical inter ballistics model of steady deflagration traveling charge was established and solvated by the corresponding program made in this paper. The calculated results showed that the deflagration traveling charge could increase the initial velocity of projectile remarkably. It's a grest future gun propulsion technique.

122. Detonation Wave Emissivity and Detonation Temperature Measurements by Imaginary Auxiliary Source Reflection Method

YUAN Bao hui, YUAN Tian you, ZHU Ming wu
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Based on optic principle, the method of detonation wave emissivity and detonation temperature measurement by imaginary auxiliary source reflection is described. The method overcomes the difficult that the above two parameters can't be simultaneously measured by single or two colour optic pyrometers. By this method, the detonation wave emissivity and detonation temperature of liquid explosiveNM are measured, and the results are in agreement with the reference reports.

123. The Effect of Size Grading of NC Powder on the Combustion Charateristics of RDX CMDB Propellant

Guan Dalin Liu Xiaogang Chen Xueli Zhang Shuangjian
Xi'an Modern Chemistry Research Institute, Xi'an 710065

Abstract: Using size grading of NC powder, the burning rate at the pressure range of 715MPa can be raised, therefore it is useful to lower the pressure exponent of burning rate of RDX CMDB propellant.

124. Study on Combustion Characteristics of Magnesium/Aluminum Fuel rich
Propellants

Zhang Wei Zhu Hui Fang Dingyou Zhang Weihua Wan Zhangji
National University of Defense Technology, Changsha 410073

Abstract: It was studied systematically in this paper that the combustion characteristics of magnesium/aluminum fuel rich propellant. Then the fuel rich propellant composition was optimized. The experimental results showed that the contents of the AP and the magnesium in the metal additives have the most effective action on the combustion characteristics of the propellants. The greater the contents of AP and magnesium are, the higher burning rates of the propellant and the broader flammability limit. On the other hand the flammability limit of the propellant can be modified by means of increasing its burning rate, adding super fine metal of burning rate modifier.

125. Study on Effect of Different Processing Conditions on Combustion Performance of Casting-CMDB Propellants

Chen Xueli Liu Xiaogang Yu Hongjian
Xi'an Modern Chemistry Research Institute, Xi'an 710065

Abstract: Effects of different processing conditions on the combustion characteristics of casting CMDB propellants were studied in this paper. Such processing conditions include ways of treating and adding of the catalyst, the predry and kneading time, the curing time and temperature etc. The results show that processing conditions have great effects on the burning rate and pressure exponent of casting CMDB propellants.

126. Uniformity and Stability of Combustion Heat and Its Uncertainty Analyses for Mg/Al Fuel-rich Propellant

PANG Wei-qiang, FAN Xue-zhong, SUN Zhi-hua, XU Hui-xiang, ZHANG Xiao-hong
Xi'an Modern Chemistry Research Institute, Xi'an 710065, China

Abstract: Mg/Al fuel-rich propellants were prepared by means of improving the craftwork based on the experimental formulation of Mg/Al fuel-rich solid propellants. The combustion heat of Mg/Al fuel-rich propellant, which was in system sampling, was determined by means of constant temperature oxygenic bomb calorimeter. The uniformity and stability of the results were studied by variance and student′s T-test method, and the uncertainties of the test were analyzed. The results show that the combustion heat of this sort of Mg/Al fuel-rich propellants prepared had better uniformity and stability.Its extended uncertainty is less than 3.0 in case of k=2.

127. The Effect of Ambient Temperature and Boron Content on the Burning Rate of the B/Pb3O4 Delay Compositions.

Yanchun Li [School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China.], Yi Cheng [School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China.], Yun-Long Hui [School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China.], Shi Yan[School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, P.R. China.], Journal of Energetic Materials; Apr-Jun2010, Vol. 28 Issue 2, p77-84

Abstract: The burning rates of B/Pb3O4 delay compositions were investigated. Boron content was varied from 1 to 16% and the ambient temperature from -50°C up to 70°C. The measured burn rates increased as both parameters were increased and ranged from 1.28 to 3.12 cm/s. The data were correlated using an empirical model.

128. A Simple Method to Estimate the Critical Temperature of Thermal Explosion for Energetic Materials Using Nonisothermal DSC.

Xue, L.[Xi'an Modern Chemistry Research Institute, Xi'an, P.R. China.]
Zhao, F. Q.[Xi'an Modern Chemistry Research Institute, Xi'an, P.R. China.], Hu, R. Z. [Xi'an Modern Chemistry Research Institute, Xi'an, P.R. China.], Gao, H. X. [Xi'an Modern Chemistry Research Institute, Xi'an, P.R. China.], Journal of Energetic Materials; Jan-Mar2010, Vol. 28 Issue 1, p17-34

Abstract: A method for estimating critical temperature (Tb) of thermal explosion for energetic materials was derived from Semenov's [9] thermal explosion theory and the nonisothermal kinetic equation [image omitted] based on Berthelot's expression using reasonable hypotheses. The final formula is [image omitted], which is simple. We can easily obtain the onset temperature (Tei) from the nonisothermal DSC curves, the value of Te0 from the equation [image omitted], the values of b from the equation [image omitted], and then calculate the value of Tb. The result obtained with this method coincides completely with the value of Tb obtained by Zhang et al.'s [4] method.

129. Generation of BN in the Combustion Residue of Boron-Containing Propellant

Xing Xi [Department of Chemical Physics, University of Science and Technology of china, Hefei, China]; Li Shufen [Department of Chemical Physics, University of Science and Technology of china, Hefei, China], Journal of Energetic Materials, Volume 21, Issue 1 January 2003 , pages 63 - 72

Abstract: Residue analysis of boron-containing propellant burned in the primary and aft-mixing combustors of a solid propellant ramjet (SPRJ) indicated that a considerable amount of boron nitride (BN) was created in addition to the main product of B 2 O 3 . The formation heat of BN is far less than that of B 2 O 3 , which brings some disadvantage to the heat release of boron. Ignition and combustion of boron are carried out in an oxygen bomb Calorimeter. Thermoanalysis, X-ray diffraction, elementary analysis, and X-ray photoelectron spectroscopy are adopted to investigate the source of BN, the effect of air pressure, and the effect of oxidizers. The results show that the output of BN increases with the rising of air pressure, N 2 is proved to be the main origin of elemental nitrogen in forming BN, and a competition effect exists between the oxidation and nitrification of boron.

130. Thermal behavior of hmx and metal powders of different grade

Jiang Zhi [Department of Chemistry Physics, University of Science and Technology of China, China]; Li Shu-fen [Department of Chemistry Physics, University of Science and Technology of China, China]; Zhao Feng-qi [Xi'an Modern Chemistry Research Inst, Xi'an, China]; Chen Pei [Xi'an Modern Chemistry Research Inst, Xi'an, China]; Yin Cui-mei [Xi'an Modern Chemistry Research Inst, Xi'an, China]; Li Shang-wen [Xi'an Modern Chemistry Research Inst, Xi'an, China], Journal of Energetic Materials, Volume 20, Issue 2 2002 , pages 165 - 173

Abstract: The thermal decomposition characteristic of HMX influenced by the addition of aluminum, nickel, copper with different particle size (general and nano-meter) are studied by PDSC and TG. The results showed that nano copper had the greatest influence on the condensed-phase decomposition characteristic of HMX among the metal powders. Such catalysis effect will be weakened by the decrease of the content of metal powder or the increase of system pressure. Based on the kinetics result inferred from the isothermal DSC experiment, the mechanics of such influence are attributed to the efficacy of catalysis effect, secondary effect and reaction site effect.

131. Safety assessment studies of a damaged high-energy solid propellant

T. H. Zhang [State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing, China]; S. Y. Wang [Xi'an Modem Chemistry Research Institute, Xi'an, China] ; P. D. Liu [Xi'an Modem Chemistry Research Institute, Xi'an, China], Journal of Energetic Materials, Volume 20, Issue 2 2002 , pages 175 - 189

Abstract: This article presents a study of the effects of damage on the thermal decomposition, combustion and deflagration-to-detonation transition (DDT) of the NEPE (Nitrate Ester Plasticized Polyether) propellant in order to assess its safety. The study includes: (1) to induce damage into the propellants by means of a large-scale drop-weight apparatus; (2) to observe microstructural variations of the propellant with a scanning electron microscope (SEM); (3) to investigate thermal decomposition tests; (4) to carry out closed-bomb tests and (5) to perform DDT tests. The NEPE propellant is found to be a viscoelastic material. The matrices of damaged samples are severely degraded, but the particles are not. The results of the thermal decomposition tests, closed-bomb tests and DDT tests show that the microstructural damage in the propellant has some marked effects on its thermal decomposition rate, bum rate and transition rate from deflagration to detonation. It is shown that the impact damage strongly influences on safety properties of the NEPE propellant.

132. Combustion mechanism of the low signature propellant containing 1, 7-diazido-2, 4, 6-trinitrazaheptane(dath)

Dang Zhi-Min [Electrical Insulation Institute, Xi'an Jiaotong University, Xi'an, China]; Zhao Feng-qi [Xi'an Modern Chemistry Research Institute, Xi'an, China]; Li Shang-wen [Xi'an Modern Chemistry Research Institute, Xi'an, China], Journal of Energetic Materials, Volume 18, Issue 1 March 2000 , pages 29 - 37

Abstract: The thermal decomposition behavior of the low signature (LS) propellant containing 1, 7-diazido-2, 4, 6-trinitrazaheptane(DATH) is investigated by DSC, TG and DTG technique. Several analysis methods are used to study the physico-chemical structure of surface before and after combustion and the burning flame structure of this kind of propellant. Because DATH decomposes to produce a great quantity of N2, the physico-chemical structure of burning surface of the propellant is obviously different from that of RDX-CMDB (Composite Modified Double-Base) propellant. It's mainly N2, that gives rise to forming a lot of pores on the burning surface for its release. These pores can increase the burning rate because of extending the burning surface and increasing thermal-transfer intensity. In comparison with decomposition and combustion process of RDX-CMDB propellant, the propellant containing DATH creates the different decomposition products from the condensed phase to the fizz zone.

133. Kinetic studies of thermal decomposition of AANTO, BAED and DAAP by ARC and DSC

Authors: Dong Shuan [Department of Chemistry, Shandong Teacher's University, Jinan, China]; Wan Xingzhongb [Institute of Chemical Metallurgy, Chinese Academy of Sciences, Beijing, China]; Ou Yuxiangc [Beijing Institute of Technology, Beijing, China]; Feng Changgenc [Beijing Institute of Technology, Beijing, China]; Wang Yunc [Beijing Institute of Technology, Beijing, China]; Chen Borenc [Beijing Institute of Technology, Beijing, China], Journal of Energetic Materials, Volume 17, Issue 1 March 1999 , pages 87 - 103

Abstract: In this paper, three new organic azids i. E. 2-azidoethylammonium-3-nitro-1, 2, 4-triazol-5-onate (AANTO), 1, 1-dinitro-3-aza-5-azidopentane (DAAP) and bis (2-azidoethylamine)-ethyl-dinitramine (BAED) are synthesized and characterized, and their thermal decomposition reactions are studied using DSC and ARC. The approximate heat of decomposition is determined, and the the self-heating rates and pressure increasing rates are measured as the function of self-heating temperature. Their thermal stability is compared, and their potential thermal hazard is assessed.

134. Quantitative analysis of tin and lead in TDI combustion catalyst

Li Qin-fang [Xian Modern Chemistry Research Institute, Xian, P. R. China], Journal of Energetic Materials, Volume 15, Issue 2 & 3 June 1997 , pages 179 - 183

Abstract: A convenient method for quantitative analysis of tin and lead in 2, 4—tolylene diisocyanate (TDI) combustion catalyst, which contains Tin, lead and their compounds or complexes, is described. The method consists of decomposition of samples by sodium hydroxide fusion, extraction with hydrochloric acid and complexation by EDTA, followed by titration with zinc chloride standard titration solution, which give rise to a precise content of tin and lead respectively in one conical flask.

135. Study of Combustion Properties of a Solid Propellant by Highly Time-Resolved Passive FTIR

Liming Zhang, Lin Zhang, Yan Li, Bingping Liu, Junde Wang [Laboratory of Advanced Spectroscopy, Nanjing University of Science & Technology, Nanjing 210014 (P. R. China)], Propellants, Explosives, Pyrotechnics, 31: 410–414.

Abstract: With a time resolution of 0.125 s and a spectral resolution of 4 cm−1, emission spectra of the combustion process of a solid propellant were recorded by highly time-resolved passive FTIR. Some gaseous combustion products, such as H2O, CO, CO2, NO and HCl, were distinguished by the characteristic emission band of each molecule. The equation for flame temperature calculation based on the diatomic molecule emission fine structure theory was improved through judicious utilization of the spectral running number ‘m’ which makes the temperature measurement simpler and faster. Some combustion information of the solid propellant had been given including the characteristic spectral profile, the distribution of the absolute spectral energy, the distribution of the combustion flame temperature, and the concentration distributions of HCl and NO versus burning time. The results will provide theoretical and experimental bases for improving the formula and raising combustion efficiency of solid propellant, and developing the design of rocket motor, infrared guidance and antiguidance systems.

136. Damage of a High-Energy Solid Propellant and Its Deflagration-to-Detonation Transition

Taihua Zhang, Yilong L. Bai [State Key Laboratory for Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, P.R. China], Shiying Y. Wang, Peide D. Liu [Xi'an Modern Chemistry Research Institute, Xi'an 710065, P.R. China], Propellants, Explosives, Pyrotechnics, 28: 37–42.

Abstract: In order to assess the safety of high-energy solid propellants, the effects of damage on deflagration-to-detonation transition (DDT) in a nitrate ester plasticized polyether (NEPE) propellant, is investigated. A comparison of DDT in the original and impacted propellants was studied in steel tubes with synchronous optoelectronic triodes and strain gauges. The experimental results indicate that the microstructural damage in the propellant enhances its transition rate from deflagration to detonation and causes its increased sensitivity. It is suggested that the mechanical properties of the propellant should be improved to reduce its damage so that the probability of DDT might be reduced.

137. Experimental Research of the Effects of Superfine Aluminum Powders on the Combustion Characteristics of NEPE Propellants

Fang Chong, Li Shufen [Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (P. R. China], Propellants, Explosives, Pyrotechnics, 27: 34–38.

Abstract: The combustion behavior of grading aluminum powders containing superfine aluminum powder (SAl) in NEPE propellant has been studied by several kinds of experimental techniques. The results indicate that the usage of grading aluminum powders containing SAl can effectively improve the combustion characteristics of NEPE propellant and the combustion efficiency of aluminum. The reason is that SAl has the different combustion and thermochemical properties from those of generally powdered aluminum (Al). SAl is inclined to burn in a single step, hence greatly increasing the heat released during the thermal decomposition of NEPE propellant.

138. Aluminum Oxidation in Nitramine Propellant

Zhu Ji, Li Shufen [Department of Chemical Physics, University of Science and Technology of China, Hefei 230026 (People's Republic of China)], Propellants, Explosives, Pyrotechnics, 24: 224–226.

Abstract: In spite of the numerous literature on the oxidation of aluminum in sold propellant combustion, these researches mainly focus on aluminum in AP-based composite propellant and little is known about aluminum oxidation in nitramine propellant. The purpose of this note is to discuss some possible reactions of aluminum in such circumstances.

139. The Influence of DDT-Preventing Agents upon the Impact Sensitivity of the polyurethane-bonded RDX

Li Wen, Song Quancai, Wang Wenbin, Chen Yongke [College of Chemical Engineering and Material Science, Beijing Institute of Technology, Beijing 100081, (People's Republic of China)], Propellants, Explosives, Pyrotechnics, 21: 247–250.

Abstract: The effect of some DDT-preventing agents (DPAs) and their mixtures on the impact sensitivity of RDX/PU has been studied. All specimen for drop-hammer test were prepared by solvent-slurry method. Two ways were used in adding DPA. The behavior of moulding powders obtained to the mechanical impact were assessed using KAST Impact Hammer. The results have shown that some DPA decreased the impact sensitivity of RDX/PU with different degree, and the loading way of DPA also had obvious effect on it. Finally, the characteristic heights H50 and the remained quantities of samples after impacting were analyzed and discussed.

140. Research on the Crack Mechanism of High-Burning-Rate Propellant in the solid rocket motor

D. A. Wang, N. F. Wang, G. M. Qin [Xi'an Modern Chemistry Research Institute, Xi'an (P.R. China)], Propellants, Explosives, Pyrotechnics, 20: 11–15.

Abstract: Through the analysis and calculation to the flow field in the solid rocket motor using high-burning-rate propellant, the authors believe that the existence of pressure difference between the inside and outside of the propellant tube causes the propellant crack. In this paper, the design method to eliminate the pressure difference is discussed. The theoretical results were certified by the experimental results.

141. The energy and pressure exponent of composite modified double-base propellant†

Hou Zhulin, Feng Zeng-guo, Wang Enpu, Han Panming [Chemical Engineering and Material Science College, Beijing Institute of Technology, Beijing 100081 (P. R. China); †Presented, in part, 10th International Seminar on Defence Science and Technology, held at Wah Cantt, Pakistan, Dec.2–4, 1990.], Propellants, Explosives, Pyrotechnics, 17: 59–62.

Abstract: The paper describes an analysis on the energy and pressure exponents of composite modified double-base (CMDB) propellants. The evaluation of the energy was conducted by means of a thermodynami- cal program. Propellant burning rates were determined by the strand burner method. In the AP-based composition, the energy is enhanced and the pressure exponent reduced with increasing AP content. When AP is partially or entirely replaced by the nitramines HMX or RDX, Isp is improved, and the pressure exponent is inevitably increased. A mixture of lead salicylate or lead o-amino benzoate and copper 2, 4- or 3, 5-dihydroxy benzoate produces a remarkable effect on the burning nature of the CMDB propellant. It was noted that the pressure exponent decreases from 0.66 to 0.48 with lead and copper salts added at 3.0% in AP-Al, 0.82 to 0.60 at 2.0% in RDX-Al and 0.72 to 0.54 at 2.5% in RDX-AP-Al compositions, respectively.

142. Combustion Mechanism of Double-Base Propellants with lead burning rate catalysts

Cai Youfang [Department of Chemical Engineering, Beijing Institute of Technology, Beijing (China)], Propellants, Explosives, Pyrotechnics, 12: 209–214.

Abstract: On the basis of relevant experimental phenomena and results, which also include the results on the domain of non-propellant combustion, this paper has determined basic reactions caused by lead burning rate catalysts in the combustion process and their approximate reaction temperature. In the presence of carbonaceous matter on the burning surface the partial NO is reduced to N2 through six reactions occurred on the carbonaceous matter instead of the reaction between NO and CO. As a result of changing the reducing path of a part of NO the burning rate rises through increasing the temperature gradient in the fizz zone at the burning surface. The reactions between PbO and C and between PbO and CO check the burning rate to rise through expending carbonaceous matter on the burning surface and causing char particles to “fly off” the burning surface. The super-rate, plateau and mesa effects are perfectly explained with these reactions and the fundamentals of heat transference. The production of the effects arises from the competing of two actions to increase burning rate and to check the burning rate enhancement of lead burning rate catalysts and the effect of the pressure on the burning rate. Because of the fact that the chance to form carbon nuclei and the time of the carbon deposit, the covering ratio of the carbonaceous matter on PbO particles, and the temperature increasing rate and the lagging temperature difference in C-PbO interfaces depend on the pressure, the ability by the reaction between PbO and C and between PbO and CO checking the burning rate to rise makes a great difference in different ranges of the pressure. In addition, according to the combustion mechanism advanced in the paper the effects of the physical and chemical properties of lead burning rate catalysts, especially their ability to absorb the ultraviolet light, on the rate-increased values and the pressure ranges of the plateau and the mesa regions have been expounded.

143. Combustion Characteristics of High-energy Smokeless Modified Double-base Propellant at Middle and High Pressures

Xiao-long , SHAO Chong-bin , WU Shu-xin , FAN Xue-zhong , LI Ji-zhen , YU Hong-jian , LIAO Lin-quan , Chinese Journal of Energetic Materials, 2010, 18(1):107~109

Abstract: The combustion characteristics of the high-energy smokeless modified double-base propellant (HESMDB) at 10-43 MPa was studied. Results show that the burning rate of HESMDB increases with pressure enhancement. There is an inflexion point in the combustion curve of HESMDB propellant at 25 MPa, and then the burning rate of HESMDB increases rapidly. The effects of combustion catalyst is obvious on HESMDB at 10-25 MPa, and lessened at 25-43 MPa. NI-Pb/NI-Cu/CB enhances the burning rate of HESMDB 75.16% at 10 MPa

144. Relationship between Burning Rate and Combustion Wave Characteristic Value of Double-base Propellant with Low Burning Rate and Low Flame Temperature

QIN Neng , ZHANG Chao , WANG Ming-xing , Chinese Journal of Energetic Materials, 2010, 18(1):110~114.

Abstract: To study the relationship between the burning rate and the characteristic value of combustion wave, the combustion wave structure of double-base propellant with low burning rate and low flame temperature were obtained by using the technology of imbedded minimized thermal couples into propellant, and the experimental data were calculated and the characteristic value of combustion wave, the surface temperature, the dark zone thickness, the temperature grades of condensed phase and gas phase fizz zone, were obtained. Burning rate of propellants without catalysts increases with the surface temperature increasing，and the surface temperature of propellants with catalysts is higher than that of propellants without catalysts. Flame temperature enhances with increase in pressure, and there is not necessary relationship between flame temperature and burning rate. Results show: the relationship between the burning rate of the said double-base propellant with low burning rate and low flame temperature and the characteristic value of combustion wave is rather complex, and there are linear and non-linear relationships when combustion performance changes. The reason is that combustion wave structure is changed with catalysts.

145. Preparation of Ultrafine Calcium Carbonate with Different Shapes and Their Applications in the HTPB Propellant

LI Xiao-dong, YANG Rong-jie and YANG Yan, Chinese Journal of Energetic Materials, 2009, 17(1):64~68.

Abstract: Ultrafine calcium carbonate particles prepared by micro-latex method were determined by means of X-ray diffraction (XRD) and scan electron microscopy (SEM). HTPB propellants with different kinds of calcium carbonate particles were studied. They included ordinary calcium carbonate, cubic ultrafine calcium carbonate, spherical ultrafine calcium carbonate and spherical ultrafine calcium carbonate treated by emulsifying agent. The results show that shapes of ultrafine calcium carbonate particles include clava, spindle, ellipsoid, bamboo-like, sphere, arborization, coral-like, conglutinate, cube and flake. The crystal forms of ultrafine calcium carbonate particles are calcite and aragonite and particle size is less than 1 μm. The experimental condition affects the shapes of ultrafine calcium carbonate particles. The burning rates of HTPB propellant decrease by 29.6%, 39.3%, 46.2% and 48.6% at 7 MPa, respectively, when 3% ordinary calcium carbonate, cubic ultrafine calcium carbonate, spherical ultrafine calcium carbonate and spherical ultrafine calcium carbonate treated by emulsifying agent were added to HTPB propellant. Different kinds of calcium carbonate particles may decrease the burning rate of HTPB propellant. The burning rate of HTPB propellant with ultrafine calcium carbonate decreases more than that with ordinary calcium carbonate. Ultrafine calcium carbonate particles treated by different methods affect the burning rate of HTPB propellant little.

146. Effects of Nano-carbonate Catalyst on the Properties of AP/Al/HTPB Propellants

CAO Xin-fu, HE Yao-dong, YANG Yi, LI Feng-sheng, ZHANG Zhan-quan and SONG Ji-ge, Chinese Journal of Energetic Materials, 2009, 17(1):69~72

Abstract: The study of the effects of nano-carbonate burning rate catalysts on the pressure exponent, heat of explosion and mechanical properties of the AP/Al/HTPB propellants were conducted. The results show that the catalyst can reduce the burning rate pressure exponent of the propellants to 0.20 in the pressure ranges of 4-10 MPa and 10-18 MPa. The combustion efficiency and the heat of explosion of the propellants increase as the increasing of the content of the nano-catalyst. It also shows the nano-catalyst has some effects on the mechanical properties and processing properties of the propellants. It has found that the suitable weight fraction of nano-carbonate catalyst in the propellants is 0.5%-1%.

147. Electrical Conductivity of Combustion Products of Composite Propellant Containing Cs Salt

ZHOU Lin, XIE Zhong-yuan and SHAO Qing-xin, Chinese Journal of Energetic Materials, 2009, 17(1):99~102

Abstract: The electrical conductivity of combustion products of composite propellant containing Cs salt which used in magneto-hydro-dynamic (MHD) generator were calculated through Sahe equation and model of electrical conductivity. The basic thermodynamic parameters used in the model of electrical conductivity were calculated by applying thermodynamic equilibrium constant equation. Through theoretical calculation, the change of electrical conductivity along with the Cs salt content and aluminum content was obtained. The results show that for the given aluminum content, the optimal range of Cs salt content(mass percent) is 5%-10%; the higher combustion temperature and lower pressure of combustion chamber promote higher electrical conductivity.

148. Characterization of Combustible Cartridge Cases Enhanced by Novel Energetic Fibers

LI Yu, GUO De-hui, ZHAO Cheng-wen, ZHOU Wei-liang and XU Fu-ming, Chinese Journal of Energetic Materials, 2009, 17(3):334~338

Abstract: In order to improve mechanical properties and combustion performance simultaneously，novel combustible cartridge cases were manufactured by adding energetic fibers as reinforcement component. The mechanical properties were characterized by compression and tensile strength，and combustion performance was evaluated by closed-bomb and gun charge cartridge tests. Results show that these novel combustible cartridge cases have good mechanical properties，and combustion performance is also improved. With increasing of the energetic fibers content，the ignition time and burning-off time are shrunk more and more，and the burning rate and impetus of the case are increased gradually. Compared with the original ones，fewer solid residues and combustible gas are found in gun charge cartridge tests，which means adding energetic fibers could decrease the shooting features.

149. Summarization of Laser Ignition Characteristics of Solid Propellants

HAO Hai-xia, PEI Qing, ZHAO Feng-qi and LI Shang-wen, Chinese Journal of Energetic Materials, 2009, 17(4):491~498

Abstract: Laser ignition has been an active research topic in recent years, and laser becomes an attractive future alternative ignition source to study the ignition characteristics of propellants because of its advantages of high and adjustable energy, the ignition time and energy being controllable, and the ignition process unlimited by the surroundings. In addition, the studies of ignition characteristics of propellants contribute to explaining the combustion theory and demonstrating the related model. The brief theory, the characterization and the apparatus of laser ignition of solid propellants at home and abroad were described. And the factors affecting the laser ignition of propellants such as the laser energy, the components and contents of propellants and the circumstances including pressure and temperature, were discussed. In the end, several problems on the evolvement of the laser ignition characteristics of the solid propellants were summarized and concluded with 50 references.

150. Electric Spray Ionization Mass Spectrum of Picric Acid and Styphnic Acid

LIU Jun-wei, ZHANG Jian-guo, ZHANG Tong-lai, ZHANG Dan-dan and YANG Li, Chinese Journal of Energetic Materials, 2009, 17(5):594~598

Abstract: In order to understand the combustion and explosion mechanisms of energetic materials, the cracking pathways of 2, 4, 6-trinitrophenol(PA) and 2, 4, 6-trinitroresorcin(H2TNR) were studied by electric spray ionization mass spectrometry(ESI-MS), and their cracking mechanisms were analyzed. Results show that cracking modes of the two compounds were loss of NO2, OH, O, NO, CO, CNO and CNO2, and those with a hydroxy group ortho to the nitro group exhibit predominant “ortho effect”, and the facile transfer of a hydroxy hydrogen to oxygen followed by loss of OH. When the number of nitro groups is definite, “ortho effect” becomes more important with increasing of the number of the ortho hydroxy groups, and the compounds are more easily to lose OH rather than lose NO2 firstly.

151. Combustion Characteristics of Thruster with High Burning Rate Pyrotechnics

LIU Ling, LI Guo-xin, JIANG Xin-guang and LAO Yun-liang, Chinese Journal of Energetic Materials, 2009, 17(6):704~707

Abstract: In order to study the regulation of burning rate and combustion characteristics in high burning rate work device, and ensure the thrust output stability of the device, a burning rate test by optical fiber was introduced and the ignition-combustion rate of pyrotechnic short-pulse propelling work device was tested. Results show that the combustion process has a non-parallel layer burning characteristic, and the distributions of burning rate exist in three different diagnostic burning zones (the parallel layer combustion zone, the transition combustion zone and the stable convection zone) along the burning direction, the stable burning rate of the propelling device reaches the maximum when the charge density is 1.45 g•cm-3.

152. Combustion Process of Fog Aerosol and Its Influence on Condensation Nucleus Growth Behavior

DAI Meng-yan, HU Bi-ru, ZHANG Xue-ao and WU Wen-jian, Chinese Journal of Energetic Materials, 2009, 17(6):708~712

Abstract: By using of high-speed photograph techniques, thermogravimetric analysis (TG), differential thermal analysis(DTA) and scanning electron microscope (SEM), the combustion process of fog aerosol and formation of condensation nucleus were investigated. Results show that the high temperature and pressure air mass with a large amount of high temperature condensation nucleus is produced after the combustion of fog aerosol, and the temperature and pressure decrease rapidly with the air mass ascending. The particle size distribution of condensation nucleus is 0.2-1 μm and its main component is NaCl. The growing process of condensation nucleus and the forming of fog droplet are related with the supersaturation produced by the cooling and expanding of the air mass.

153. Effect of Magnesium Powder Particle Size on Combustion Properties of Mg/PTFE Fuel-rich Propellant

ZHENG Lei, PAN Gong-pei, CHEN Xin and QIAO Li, Chinese Journal of Energetic Materials, 2010, 18(2):180~183

Abstract: The effect of magnesium powder particle size on the combustion properties of Mg/PTFE fuel-rich propellant was studied. The thermal properties of Mg/PTFE were studied by using differential thermal analysis(DTA) and thermogravimetry(TG). The linear and molar burning rate were measured by high speed photography, and the flame temperature was surveyed by infrared radiation thermometers. The results show that reducing magnesium powder′s size had little weight on thermal analysis but steps up burning velocity even more than three times. The flame temperature of pyrotechnic fuel rich propellant heighten about 170 ℃ along with the diameter of magnesium powder decrease.

154. Effect of Performance with Eliminated-flame Additive on Nitramine Modified Double Base Propellant

LI Jun-qiang, LI Xiao-jiang, LIU Peng, QI Xiao-fei and LIU Fang-li, Chinese Journal of Energetic Materials, 2010, 18(3):290~294

Abstract: Four traditional eliminated-flame additives(LiF, KA, C4O6H4K2 and KD) were adopted in grain cast propellant, and its effects on the combustion performance and characteristic signal of the propellant were studied. The motor experiment results show that KA and KD suppress after burning. More than 80% flame area were reduced. Burning rate of propellant is increased with the eliminated-flame additives. Results show IR and visible light permeation rate of grain cast propellant is slightly reduced, and laser permeation rate is increased.

155. Effects of Oxidants on Combustion Performances of Al/H2O Based Fuels in Air

LIN Zhen-kun, HAN Dong-lin, WANG Tian-fang, ZHAO Feng-qi, YI Jian-hua and LI Shu-fen, Chinese Journal of Energetic Materials, 2010, 18(3):295~299

Abstract: Effects of the oxidant (HMX or CL-20) on the combustion performances of Al/H2O based fuels were studied by a series of experimental techniques in air atmosphere. The experimental results show that, compared with CL-20 addition, HMX makes Al powders burn much thoroughly, and it has better effect in increasing the temperature of burning surface. However, CL-20 addition makes the heat transfer faster than HMX and improves the burning rate markedly. The experimental results are considered to be closely related to the thermal decomposition and combustion characteristics of CL-20 and HMX.

156. Combustion Behavior of the Low-Smoke Level Fuel-Rich Composite Propellants at Low Pressure

ABDEL WARETH W. M. and XU Xu, Chinese Journal of Energetic Materials, 2010, 18(3):300~303

Abstract: The combustion behavior of composite fuel-rich propellants based on hydroxy-terminated polybutadiene pre-polymer (HTPB)/ammonium perchlorate oxidizer (AP) studied experimentally at 0.1-1 MPa. Results show that high content and small particle size of AP, high pressure promotes sustained combustion and increases burning rate, combustion efficiency and decreases ignition temperature. The copper chromite (CC) as a burning rate accelerator, moderately, increases the burning rate over the whole pressure regime. Moreover, it creates an acceptable combustion efficiency of about 96%. 6% CC decreases ignition temperature by about 16%. It is indicated that the Vieille burning rate law for this propellant family may be extended to extremely low pressures and combustion efficiency marked from "highly poor" to "poor" for the formulations without copper chromite.

157. Combustion Characteristics of B/KNO3 in Microscale Tube

LIU Jian, SHEN Rui-qi, YE Ying-hua and HU Yan, Chinese Journal of Energetic Materials, 2010, 18(3):335~338

Abstract: To understand combustion characteristics of igniter in microscale tube, B/KNO3 combustion in microscale tube were obtained from high-speed photography. Results show that wall heat loss and tube resistance are the main affecting factors for combustion stability. Combustion is stable in 1.0-2.0 mm quartz tube, and B/KNO3 burning rate varies weakly. B/KNO3 burning rate is proportional to combustion chamber pressure among 0.1-4 MPa, however, it is not consistent with exponent law. Combustion is unstable when the inner diameter of quartz tube is decreased to 0.5 mm, and the burning rate is increased with increasing of time. When the inner diameter of quartz tube is reduced further, breakdown phenomenon is produced and combustion quenching is caused. In addition, B/KNO3 burning rate is in inverse proportion to wall thickness in the certain extent.