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1.
泡沫发射药因其独特的气孔L结构,比常规的硝化纤维发射药有更高的燃速与钝感性能,可用作高燃速发射药和无壳弹药.主要介绍了泡沫发射药研究方面的进展以及影响其性能的主要因素. 相似文献
2.
The effects of porous structure on the burning characteristics of foamed NC‐based (nitrocellulose‐based) gun propellants were investigated by closed vessel and quenched combustion experiments. The foamed NC‐based TEGDN (triethylene glycol dinitrate) gun propellants with different porous structures were prepared by adjusting the process parameters in the foaming process. SEM (scanning electron microscopy) was used to observe the morphologies of foamed TEGDN propellants, and the densities of the foamed propellants were also measured to evaluate the porosities of foamed propellants. The experimental results showed that the burning characteristics of the novel foamed propellants are totally different from combustion characteristics of parallel‐layer. Further investigations revealed that the burning characteristics of the foamed NC‐based propellants largely depend on the porous structure, larger pores and higher porosity would lead to higher burning rate of the foamed TEGDN propellants. 相似文献
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Foaming properties of the three NC‐based (nitrocellulose‐based) propellants, namely, single‐base propellant, NG (nitroglycerine) propellant and TEGDN (triethylene glycol dinitrate) propellant were investigated in the batch foaming process by using supercritical CO2 as the physical foaming agent. Burning characteristics of the foamed NC‐based propellants were also investigated in this work. For this study, the CO2 desorption of the three NC‐based propellants were plotted by the gravimetric method. The morphology and burning characteristics of these foamed NC‐based propellants were characterized by scanning electron microscope (SEM) and closed vessel experiment. The test data revealed that the energetic plasticizer has a considerable effect on the pore formation in the NC matrix although it has little effect on the CO2 solubility in the NC‐based propellants. Moreover, the SEM images showed the foaming temperature also plays an important role in the pore parameters of foamed propellants. Furthermore, the data of closed vessel experiment indicated that the burning characteristics of foamed NC‐based propellants largely depend on the pore parameters, and the porous structure of foamed propellants would considerably increase the mass conversion rate. 相似文献
4.
Norbert Eisenreich ThomasS. Fischer Gesa Langer Stefan Kelzenberg Volker Weiser 《Propellants, Explosives, Pyrotechnics》2002,27(3):142-149
In the past, Vieille's law and minor modifications of it described sufficiently the linear burning rate of gun propellants which governs the design of charges by interior ballistic simulations. Recent developments to increase the performance led to new gun concepts and innovative propellants. These are the electrothermal‐chemical gun, porous and foamed charges as well as formulations exhibiting a temperature independent burning. Vieille's law cannot fully meet experimental results in these cases. Approaches based on the heat flow equation in the solid energetic material give simplified formulas to extend the validity. These burning rate models have the ability to describe the experimentally determined burning behavior at least in a simplified or qualitative way. More sophisticated methods consider complex geometrical structures in the solid or take into account the actual progress in phase behavior and reaction kinetics of heterogeneous combustion. The dependence of the burning rate on initial temperature, on phase transitions, porous structure and gaseous reactions can be described. 相似文献
5.
To improve the combustion behaviors of conventional consolidated propellants, consolidated propellants were prepared using porous propellant grains as fast‐burning filler. The porous propellant grains were prepared by supercritical fluid foaming process and exhibited the high burning rate. The multi‐perforated structure of the consolidated propellants was designed and adopted to obtain high burning progressivity. To investigate the burning characteristics of the consolidated propellants, closed vessel and quenched combustion experiments were carried out. The results show that deconsolidation of the consolidated propellants does not occur, and that the consolidated propellants exhibit high burning rates and high burning progressivities. Besides, the results show that the consolidated propellants burn steadily even at low (−40 °C) and high temperatures (50 °C). 相似文献
6.
通过配方调节与工艺控制得到3种不同结构的泡沫发射药,讨论了泡孔结构形成的影响因素;采用密闭爆发器实验和恒压燃速测试实验研究了不同结构泡沫发射药的燃烧性能。结果表明,控制气体生成速率、添加RDX颗粒、调节NC含氮量和发泡时间能够有效控制泡沫发射药的泡孔结构;皮芯结构泡沫发射药具有渐增燃烧特性,发泡区的动态活度可达不发泡皮层的2.4倍以上;独立泡孔结构的泡沫发射药在100MPa下燃速可达未发泡样品的30倍;非独立孔隙结构的泡沫发射药不同方向上的燃速差异显著,密度为1.37g/cm~3的样品100MPa下轴向燃速最高可达3.860m/s。 相似文献
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Jing Su Sanjiu Ying Zhenggang Xiao Fuming Xu 《Propellants, Explosives, Pyrotechnics》2013,38(4):533-540
Micro‐porous propellants containing titanium powder were obtained by supercritical CO2 (SC CO2) foaming technique. The morphologies of the micro‐porous propellants were characterized by scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDS) measurement. The burning rate, the impetus, and the heat of explosion of the micro‐porous propellants were measured by the closed vessel test and the calorimetric bomb test. The results show that the porosity increased with increasing titanium powder content; compared with Benite, the burning rate was substantially improved, and the maximum values of the impetus and the isochoric heat of explosion increased by 51.4 % and 6.5 %, respectively. The Ti‐containing micro‐porous propellants with rapid burning rate and better energetic properties described in this paper may have the potential to replace Benite as igniter material in a flame igniter of a gun propellant charge. 相似文献
9.
A microcellular combustible ordnance material composed of 70 % RDX (cyclotrimethylene trinitramine) and 30 % PMMA (poly methyl methacrylate) was fabricated using the solvent method and foamed by supercritical CO2 as foaming agent. This material has a number of advantages and many find potential application in weaponry. In this paper, vented bomb tests were conducted on the porous materials to gain a qualitative understanding of how the material is burning in a gun environment. The extinguish process showed that the microcellular combustible material followed the in‐depth combustion mode, i.e. the combustion products infiltrated through inner pores as well as ignited the inner pore surface. With increasing burning degree, the depth and perforation size of infiltration zone increased. Closed bomb tests were also conducted to investigate the influences of test conditions on the burning behaviors. The results showed that when the ignition pressure was increased from 10.98 MPa to 15.0 MPa, the burning time was shortened, but the mass burning rate and vivacity did not change obviously. Mass burn rates at different loading densities indicated that while the pressure in closed vessel is high enough (p≥40 MPa), hot combustion gases were driven into the inner pores and convectively ignited the inner pores. The closed bomb results conducted at high and low temperature showed no abnormal burning behavior at low and high temperature can be observed. 相似文献
10.
Volker Weiser Norbert Eisenreich Sascha Poller Stefan Kelzenberg Roger Lo Harry Adirim 《Propellants, Explosives, Pyrotechnics》2002,27(3):150-155
Cryogenic Solid Propellant (CSP)‐technology is a new approach to develop more powerful rocket motors. CSPs include the advantages of classical solid propellants to save weight as well as those of a high energy content and safety of modern liquid propellants. The charges consist of liquid and/or gaseous fuels and oxidizers, both frozen. Two main versions of CSP‐technology can be realised: 1. Mono‐CSPs show the burning behavior of solid propellants. Experiments with mono‐CSPs have been carried out under inert pressure conditions in a window bomb. Mono‐CSPs have a stable burning behavior with a constant regression rate which follows the Vieille's law under varying pressure conditions. 2. The advantage of high safety is obtained by assembling oxidizer and fuel in sandwich configurations. The grain geometry governs the burning behavior. Such systems can be externally controlled, e.g. by the heat from a gas generator or they can work self‐sustained. A Rod‐in‐Matrix burner shows self‐sustained combustion in an inert pressure atmosphere with overall burning rates in a similar range as solid rocket propellants which obey also a Vieille‐like pressure law. Disc stack burners have also been investigated, the combustion of which is strongly dependent on the disc thickness. For a short time Mach's nodes have been observed in the exhaust plume of a disc stack burner. Currently, the temperature ranges are limited to the boiling temperature of liquid nitrogen. Therefore, liquid oxidizers like H2O2 have been used. However, for the first time a propellant strand of polymer rods embedded in solid oxygen was prepared and burnt. The experiments with CSPs end in the combustion of a small rocket motor showing no serious technical obstacles. Simplified models based on the heat flow equation can simulate the burning characteristics of the frozen energetic materials including phase transitions. 相似文献
11.
Shrikant M. Pande Vaibhav S. Sadavarte Debdas Bhowmik Dashrath D. Gaikwad Haridwar Singh 《Propellants, Explosives, Pyrotechnics》2012,37(6):707-712
The burning rate pressure relationship is one of the important criteria in the selection of the propellant for particular applications. The pressure exponent (η) plays a significant role in the internal ballistics of rocket motors. Nitramines are known to produce lower burning rates and higher pressure exponent (η) values. Studies on the burning rate and combustion behavior of advanced high‐energy NG/PE‐PCP/AP/Al‐ and NG/PE‐PCP/HMX/AP/Al‐based solid rocket propellants processed by a conventional slurry cast route were carried out. The objective of present study was to understand the effectiveness of various ballistic modifiers viz. iron oxide, copper chromite, lead/copper oxides, and lead salts in combination with carbon black as a catalyst on the burning rate and pressure exponent of these high‐energy propellants. A 7–9 % increase in the burning rates and almost no effect in pressure exponent values of propellant compositions without nitramine were observed. However, in case of nitramine‐based propellants as compared to propellant compositions without nitramines, slight increases of the burning rates were observed. By incorporation of ballistic modifiers, the pressure exponents can be lowered. The changes in the calorimetric values of the formulations by addition of the catalysts were also studied. 相似文献
12.
Xiao'an Wei Di Zhang Feiyun Chen Zeshan Wang 《Propellants, Explosives, Pyrotechnics》2016,41(4):740-745
Perfusion explosives were prepared using porous SF‐3 propellants, which were synthesized by a supercritical fluid foaming process. Scanning electron microscopy (SEM) was used to characterize the porous SF‐3 propellants. Massive holes were generated after the foaming process. The density of perfusion explosives using foamed SF‐3 propellants exceeds 1.3 g cm−3, and the detonation velocities exceed 6000 m s−1. Underwater energy tests and high‐speed photography were carried out to investigate the detonation performance of perfusion explosives. The results showed that perfusion explosives using unfoamed SF‐3 propellants could not be detonated. However, perfusion explosives using their foamed analogs could be detonated herein. 相似文献
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为改善高压强下HTPB推进剂的燃烧特性,研究了碳酸盐复合调节剂、二茂铁衍生物G、高氮化合物M、纳米铝粉和纳米金属氧化物对HTPB推进剂燃烧性能的影响.结果表明,碳酸盐复合调节剂能够降低推进剂的燃速和压强指数;二茂铁衍生物G能够提高推进剂的燃速,同时将推进剂在8.60~17.12MPa下的压强指数降至0.27;高氮化合物也可降低推进剂的燃速和压强指数;将高氮化合物M与二茂铁衍生物G配合使用可将推进剂在8.63~16.48MPa下的压强指数降至0.24; 纳米铝粉和包覆的纳米金属氧化物可明显降低推进剂的燃速压强指数. 相似文献
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1,3,3-三硝基氮杂环丁烷作为增塑剂的无烟CMDB推进剂综合性能研究 总被引:1,自引:0,他引:1
对1,3,3-三硝基氮杂环丁烷(TNAZ)作为增塑剂的无烟CMDB推进剂的能量性能、安全性能、燃烧性能和热行为进行了研究,结果表明,TNAZ部分代替NG和DINA应用到无烟CMDB推进剂中,一定程度上提高了推进剂的能量,对推进剂的热稳定性影响不大,推进剂的机械感度和不同压力下推进剂的燃速均有所降低。微量量热实验研究发现,高压下TNAZ作为增塑剂的无烟CMDB推进剂的分解温度为180-235℃,其中TNAZ的分解温度大于220℃,而常压下该推进剂中的TNAZ在70~180℃时即挥发或升华。TNAZ的含量变化对TNAZ—CMDB推进剂火焰结构的影响不明显。 相似文献
17.
The thermal decomposition characteristics of RDX, binders, and RDX composite propellants were studied using thermal analytical techniques. Three kinds of binders were tested to elucidate the role of binder on the burning rate of the propellants. There were no apparent correlations between the thermal decomposition rates of binders and the burning rates of propellants, whereas there was a correlation between the decomposition temperature and the burning rate of the propellants. It is found that the major factor which controls the burning rate is the initial thermal-decomposition stage of the binders. Thus, the burning rate of nitramine composite propellants appeared to be largely dependent on the physical and chemical properties of binder. 相似文献
18.
The combustion behavior and thermochemical properties of two types of RDX-based composite propellants, XM39 and M43, are studied and compared in order to investigate the effect introduced by an energetic ingredient in the M43 propellant formulation. Due to the enhanced rate of heat release on the burning surface caused by the energetic material of M43 propellants, the burning rate of M43 propellants is found to be higher than that of XM39 propellants. The presence of the energetic material in the M43 propellant formulation also increases the burning surface temperature and thermal diffusivity of M43 propellants; it does not, however, introduce any observed changes in the flame structure and the heat feedback from the gas phase to the condensed phase. Based upon SEM pictures, burning-surface structures of the recovered XM39 and M43 propellant samples are found to be significantly different, indicating the strong effect of the energetic material on the surface reaction. A set of important thermochemical properties of XM39 and M43 propellants is deduced from the experimental data. 相似文献
19.
Andreas Koleczko Walter Ehrhardt Stefan Kelzenberg Norbert Eisenreich 《Propellants, Explosives, Pyrotechnics》2001,26(2):75-83
Electro‐thermal‐chemical (ETC) initiation and combustion offers the possibility to increase the performance of guns substantially as new propellant formulations and high loading densities (HLD) can be safely ignited and burnt in an augmented way. This paper reports investigations of burning phenomena in the low pressure region for JA2 and the effects of plasma interaction on ignition and study its influence on the burning rate. The comparison of transparent and opaque versions of the propellant is of special interest. Electrically produced plasma can strongly influence the ignition and combustion of solid propellants. Predominantly, plasma arcs influence strongly the burning of propellants by its radiation. The high intensity of the radiation initiates burning with short time delays in the µs‐range and high conversion during exposure also in the case of a stable burning. Radiation can penetrate into the propellant interior and partially fragment at absorbing structures which could be artificially introduced or be inherently present as in the case of a JA2 propellant. Simplified approaches based on the heat flow equation and radiation absorption can explain these effects at least on a qualitative scale. Dynamic effects are understood by more sophisticated models. 相似文献