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排序方式: 共有198条查询结果,搜索用时 156 毫秒
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基于火药燃烧等离子体低温、高压、瞬态的弱非理想性质,提出了综合考虑电子与离子、电子与中性粒子碰撞作用的电导率计算模型。通过计算含电离种子K_2CO_3发射药燃烧产物的电子密度和电导率,揭示了火药燃气电子密度和电导率随温度、时间的变化规律。结果表明:在2 000~3 000K范围内,火药燃气的电子密度和电导率随温度的上升而增大;火炮发射过程中,火药燃气的电子密度和电导率随时间逐渐减小,且呈非线性下降趋势。初始时刻,电子密度ne和电导率σ最大,分别为2×10~(22)m~(-3)、705.6 S/m。 相似文献
3.
利用模拟烟火药在定容、密闭条件下的数值计算方法,开发了1种以新型还原剂、硝酸钾为主的新型无硫烟花发射药配方。对该发射药的安全性能及使用性能进行测试,结果表明新型发射药的撞击感度、爆发点及静电感度安全性能均优于传统黑火药,且其压力上升速度、做功能力大于传统黑火药。 相似文献
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The experimental investigations of the effect of contact time/temperature on initiating the cook-off using 7.62 mm calibre cartridge cases (CC) were conducted previously. These cartridges were filled with commercial off-the-shelf (COTS) double based (DB) propellant (Bulls Eye) and were loaded in a hot chamber. The thermal explosion temperature is of great significance to both weapon designers and safety inspectors as it provides the operational limit and safe operating temperature. For CC under test, it was found that the cook-off temperatures of this propellant were encountered with the heat transfer profile of the simulated gun barrel between 151.4 ℃ and 153.4 ℃, with a reaction occurring in less than 300 s after the round was chambered. Usefully, each experiment was found to be consistent and repeatable. 相似文献
6.
环境保护和污染控制是建设生态型发射场的重要组成部分.分析了中国航天发射场的环境污染,针对推进剂四氧化二氮泄漏提出了采用钙基高活性粉剂处理技术,介绍了研制的系列处理装置,提出了臭氧-紫外光-活性炭联合工艺处理推进剂废水和高温燃烧处理推进剂废气废液技术,研制了移动式处理装置,解决了常规液体推进剂的发射环境污染难题,为航天发... 相似文献
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Aging induced changes in the mechanical properties of solid propellant can lead to defects, such as cracks and grain‐liner separations, that limit the service lifetime of solid rocket motors. The use of embedded sensors is one approach that is being explored by various researchers to augment legacy inspection and prediction methods. We present herein an active sensing technique that is particularly suited for monitoring the properties of solid propellant, as it does not introduce electrical wires into the motor. Based on the use of magnetic induction for excitation and an optical fiber Bragg grating sensor to measure deformation, the method can be used to characterize the properties of a material with which it is in contact. In this paper, we first present proof‐of‐principal experiments demonstrating the utility of the method in characterizing the visco‐elastic properties of an adhesive, and in following changes in viscosity of an epoxy resin during cure. We next apply the method to solid propellant, and present data demonstrating that the method can be used to measure a deflection‐load curve of an aluminized HTPB propellant. In addition, we also show that the observed strain rate sensitivity matches that found in the literature and that the method had more than adequate resolution to observe the expected changes in material properties due to aging. 相似文献
8.
Marthinus C. J. vanRamshorst Giuseppe L. DiBenedetto Willem Duvalois Peter A. Hooijmeijer Antoine E. D. M. vanderHeijden 《Propellants, Explosives, Pyrotechnics》2016,41(4):700-708
The failure mechanism of a propellant consisting of hydroxyl terminated poly‐butadiene filled with ammonium perchlorate and aluminum (HTPB/AP/Al) was determined by performing in‐situ uniaxial tensile tests in a scanning electron microscope (SEM). The experimental test plan contained uniaxial tensile test experiments performed at room temperature (25 °C) at three different strain rates (30, 150 and 750 μm min−1). The in‐situ images and in‐situ videos collected by the SEM were correlated with the stress‐strain diagrams created with the tensile experiments, in order to relate the failure mechanism to the features found in the stress‐strain diagram. No significant strain rate dependency of the failure mechanism was observed when working with strain rates up to 750 μm min−1 and working at room temperature. The stress‐strain diagram showed indications of existing cracks and voids opening up prior to the creation of new cracks and/or voids in the sample, debonding of binder with AP particles as well as nucleation and coalescence of voids. On the fracture surfaces of the samples, it was apparent that the binder cleanly separated from the large AP particles but had a better bond with the aluminum particles. However, a difference in the appearance of a short drawing phase in the stress‐strain diagram of the propellant is observed at different strain rates. The presented results clearly demonstrate the major advantage of the combination of microscopic tensile tests with microscopic observations, linking the stress‐strain behavior to the mechanical deformation processes taking place in these propellant samples at the microscopic level. 相似文献
9.
Nanduri V. Sudarsan Samir K. Das Smita D. Naik 《Propellants, Explosives, Pyrotechnics》2016,41(5):844-849
Determination of propellant formulation by ballistic requirement is an important area of research in recent times. In this study, a theoretical method for the design of gun propellant formulation using primary data of ingredients and necessary thermochemical properties of the resultant propellant was established. The employed method is based on a mathematical model of thermochemical properties of the propellant by optimizing the heat of explosion of the propellant using the fmincon tool in MATLAB. A graphical user interface (GUI) based code was generated and developed for the formulation design of solid gun propellants. The designed code was verified by available data in the literature. Such code will be useful to the researchers working in the area of high energy materials for the design of unknown propellant compositions. Further, it can be extended to redesign the existing propellant formulation in order to enhance the ballistic performance. 相似文献
10.
Wei Zhang Xuezhong Fan Hongjian Wei Jizhen Li 《Propellants, Explosives, Pyrotechnics》2008,33(4):279-285
Cyclotrimethylenetrinitramine (RDX) coated with nitrocellulose (NC‐RDX) is prepared by an internal solution method and applied in a minimum signature isocyanate‐cured propellant. It was found that RDX was coated or bonded by NC to form NC‐RDX particles; the median particle diameter (d50) and specific surface area of NC‐RDX are in the range from 150 to 240 μm and 0.03 to 0.04 m2⋅g−1, respectively. The NC‐RDX particles could swell in nitrate ester plasticizers with relatively low swelling rate compared with NC added directly in the plasticizers. Different types of ballistic modifiers can be effectively added to NC‐RDX. It was experimentally shown that NC‐RDX can increase the content of NC in the propellant with viscosities in the range from 371 to 394 Pa s and improve the mechanical characteristics of the propellant with maximum tensile strength (σm) between 0.48 MPa<σm<1.92 MPa, elongation at maximum tensile strength (εm) between 28.0%<εm<37.3%, and elastic modulus between 3.18 MPa<E<8.68 MPa in the temperature range from −40 to +50 °C. 相似文献