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大长径比点传火管的点传火性能 总被引:1,自引:0,他引:1
设计了一种点传火模拟装置,对布质点火药包、用硝基软片管封装的点火装药两种点传火装药结构进行了点传火性能试验。结果表明,同一种点火药条件下,带有硝基软片管的药管结构能够将火焰传播速度从85m/s提高到144m/s;相同装填方式下,以黑火药和奔奈药条为点火药时,传火管的火焰传播速度为205m/s,比以黑火药为点火药时提高了42.4%。采用带有硝基软片管的药管、以黑火药和奔奈药条为点火药的点传火装药结构,能够显著提高传火管的传火速度、解决传火不畅问题,使大长径比点传火管具有良好的传火性能。 相似文献
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减小高装填密度发射装药膛内压力波的实验研究 总被引:2,自引:0,他引:2
研究了两种能降低某大口径火炮高装填密度发射装药的膛内压力波的点传方案。第一种点传火方案是在制式点传火结构基础上增加横向传火具,增加点火药包;第二种点传火方案是改变制式传火结构为低爆速传火结构,同时增加横向传火具。高装填密度发射装药射击试验表明,这两种点传火方案均能满足点传火要求。第一种点传火方案较制式可燃中心传火管能实现迅速全面的点火,但出现了压力波增大的现象。而第二种点传火方案较第一种点传火方案的传火速度快,能迅速建立点火压力,发射药床的着火延迟时间小,最重要的是能抑制膛内有害压力波。压力波的频谱分析表明在高装填密度装药中,采用第二种点传火方案能削弱和抑制压力波的高频振荡成分,改善其振动特性。 相似文献
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以大口径火炮密实装药发射安全性为背景,对火药颗粒低温破碎及装药结构对内弹道特性的影响进行了数学建模和仿真分析。针对中心点传火管结构的大口径火炮密实装药,建立传火管及装药床的双一维两相流数学模型,结合膛内火药颗粒应力及破碎度函数,采用数值差分方法对内弹道过程进行数值仿真,研究火药温度及混合装药方案对火药颗粒破碎度及火炮内弹道性能的影响。结果表明,在低温条件下,单一装药结构火药颗粒将发生破碎,且破碎度随温度降低而增大,在-20℃和-40℃条件下,最大破碎度分别达到1.896和2.487,膛内压力分别为690.32MPa和803.64MPa,增幅达到16.4%;在总装药质量6.25kg不变的条件下,小颗粒药装药质量从0增至0.4kg,最大破碎度从2.487减至1.803,膛内压力从803.64MPa减至740.81MPa,由此可见混合装药结构可以有效避免火药颗粒的破碎。 相似文献
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半导体桥点火模型的建立及数值模拟 总被引:4,自引:1,他引:3
通过对半导体桥点火电路输入能量的分析,基于半导体物理学理论和非傅里叶热传导理论,认为半导体桥在输入能量大于能量临界值(E)时为等离子体点火.建立了相应的数学物理模型,采用数值分析理论对模型进行分析,得到输入能量、颗粒半径、等离子体温度等因素对点火延迟时间的影响分布曲线,这些相关的曲线分布规律证明模型建立的可行性与合理性. 相似文献
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提出了颗粒碰撞壁面过程中颗粒打破边界层和颗粒与壁面导热的强化传热模型,以分析气固两相流中颗粒强化对流传热的机理,通过模型计算研究了风速、颗粒浓度和粒径等因素对颗粒在壁面的停留特性、颗粒在边界层的扰动及对导热和边界层破坏两种强化机制传热比重的影响.以气固两相流横掠圆管的传热过程为例进行计算,计算与实验结果一致,并获得了具有实用价值的关联计算式. 相似文献
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Fu-Hu Su 《Propellants, Explosives, Pyrotechnics》1997,22(2):97-103
The conventional thermal theories are inventively modified for analyzing the ignition behaviors of solid propellants. Based on the modification of the thermal theory with the boundary condition of constant heat flux, the effects of heat flux, pressure, threshold of heat flux and absorbability on the radiant ignition of solid propellant are elaborated. The innovations of theoretical analyses are consistent with most of experimental results depicted in literatures. That the increase of hot gas velocity increases the ignition time of solid propellant is verified to be attributable to the decrease of hot gas temperature, ascertaining insight of the thermal theory with the boundary condition of flowing hot gas. In addition, a tentative estimation of pressurization rate effect on ignition time of solid propellant is proposed. 相似文献
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ETPE发射药的热分解特性与燃烧机理 总被引:2,自引:0,他引:2
通过DSC、PDSC分析了点火延迟时间长及难点火ETPE发射药燃烧过程中的热分解特性。用中止燃烧实验装置、SEM电镜观察研究了ETPE发射药燃烧表面的形貌变化及燃烧规律。结果表明,ETPE发射药热分解过程主要由其配方中含能添加剂RDX的热分解过程决定,RDX组分与含能黏结剂BAMO/AMMO聚合物体系之间的燃烧不同步性是造成ETPE发射药点火燃烧性能不佳的主要原因。根据ETPE发射药燃烧过程的特点,归纳出该类发射药的燃烧机理。 相似文献
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《Propellants, Explosives, Pyrotechnics》2017,42(9):1095-1103
The ignition and combustion property of solid propellant is the main content in internal ballistic research, which has a great significance for propulsion application and combustion mechanism. In this study, the detailed gas‐phase reaction mechanism of Nitrate Ester Plasticized Polyether Propellant (NEPE) was developed. It is helpful to understand the intricate processes of solid‐propellant combustion. The factors which may have influences on ignition delay time and temperature distribution of propellant surface was analyzed by laser ignition experiment. Using high‐speed camera and an infrared thermometer, the ignition and combustion process and the surface temperature distribution of NEPE propellant under laser irradiation were measured. Laser heat flux, ambient pressure and initial temperature of NEPE propellant have an influence on the ignition delay time and the surface temperature. Results show that the ignition delay time decreases with the increase of laser heat flux, ambient pressure and initial temperature of NEPE propellant. At the same time, with the increase of laser heat flux, the influences of ambient pressure and initial temperature on the ignition delay time decrease. Besides, laser irradiation, ambient pressure and initial temperature have significant influences on the surface temperature distribution of the propellant. 相似文献
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为提高螺压推进剂成型工艺过程的安全性,从剪切流动、绝热压缩和过热分解等视角,对推进剂在单螺杆压伸成型工艺过程中发生危险的可能性进行论述。系统地分析了药料在螺杆和模具内的流动状态,通过模拟实验,研究了推进剂在压伸过程中的热分解(着火)温度,通过实验数据分析了热分解的原因。结果表明:在药料剪切强度下降的情况下,固体床的断裂将意味着压伸的失败;在排气不畅的情况下,压伸过程的断料有可能形成绝热压缩而引发严重后果。 相似文献
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Jia Zhanning 《Propellants, Explosives, Pyrotechnics》1995,20(3):147-149
An unsteady heat conduction model is proposed to calculate the temperature distribution of the case-bonded rocket motors and the time required for the cooling process based on the experimentally determined thermal and mechanical parameters of a cast modified double base propellant (CMDB) and its glass steel shell. The resultant value of the time is then used to derive the corresponding stress relaxation modulus, which is compared with the modulus data obtained from uniaxial tensile stress relaxation experiments to see if the internal stress has been thoroughly relaxed within this period of time. 相似文献
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The process of fast ignition of double-base solid propellants (ignition time 0.6–40 msec) is studied in a model rocket chamber by means of fine thermocouples that are located on the surface being ignited and in the igniting gas stream under rapidly varying external conditions. The basic parameters of the process (propellant surface temperature, gas-propellant heat transfer coefficient, heat flux from the gas to the propellant, and the heat content and the heat release in the propellant) are obtained as functions of time. Three ignition regimes are found: fast, normal, and delayed. We discuss briefly the nature of the transition to steady-state combustion for the obtained regimes. The directions of future studies are noted.Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 29, No. 3, pp. 20–26, May–June, 1993. 相似文献
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为探究某型HTPB推进剂冲击发火的判据,对落锤试验进行了改进,在底座中引入聚偏二氟乙烯膜(PVDF)压电膜,测量推进剂受落锤冲击下的应力峰值,得到50%冲击发火的临界落高与应力;基于分离式霍普金森压杆的冲击发火试验,对比并分析了在不同的冲击应力加载条件下,推进剂临界冲击发火的影响条件,并给出该型推进剂的50%冲击发火判据。结果表明,应力峰值与特性落高的关系满足σ=175.09 H 0.5,50%特性落高为75 cm,100%不发火的最大落高为68 cm。在20、30和40 cm子弹冲击条件下,推进剂50%冲击发火的应力峰值分别为2760、2410和2120 MPa,作用持续时间分别为76、100和130μs,推进剂的冲击发火与推进剂受到的冲击应力大小和作用时间直接相关,通过σ^2τ=K判据可以较好地判断推进剂的冲击发火临界条件,且确定了K值为574.6MPa^2·s。 相似文献
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为研究火药的实际燃烧规律,建立了定容条件下火药燃烧的修正数学模型,分析了火药实际弧厚的分布及变化、点火不同步和燃速系数变化等因素对火药实际燃烧规律的影响。在此基础上,用考虑综合因素的修正数学模型对定容条件下火药的实际燃烧过程进行了模拟,计算值与实验结果具有较好的一致性,说明修正模型所建立的假设及处理方案是合理的。 相似文献