共查询到19条相似文献,搜索用时 265 毫秒
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采用火炮加载技术对JB-9014钝感炸药进行一维平面冲击实验。通过激光干涉测速仪测量冲击波到达炸药样品前、后表面的时刻以及炸药/镀膜氟化锂窗口界面粒子速度。利用冲击波到达炸药样品前、后表面的时刻差和炸药样品的厚度计算出冲击波在炸药样品中的传播速度,并结合炸药样品/氟化锂窗口接触面处粒子速度求出炸药样品冲击波后粒子速度,进而获得了炸药样品在3.1~9.7GPa压力范围内的冲击Hugoniot关系。对炸药样品中冲击波速度以及波后粒子速度进行不确定度分析,得到炸药样品中冲击波速度和波后粒子速度的合成标准不确定度约为0.54%和1.7%。将未反应炸药的冲击Hugoniot曲线和冲击波阵面的Rankine-Hugoniot关系进行联立得到冲击波后炸药样品内的压力和密度,进而拟合得到炸药样品在冲击绝热状态下沿(p,ρ)面的p-ρ曲线。 相似文献
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用激光速度干涉技术测试炸药/窗口界面粒子速度,研究炸药的冲击起爆、爆轰反应区结构、爆轰驱动和炸药反应速率等。与普通颗粒TATB相比,亚微米TATB炸药对高压短脉冲敏感,在钝感起爆器中有应用价值。文中用VISAR技术,测试亚微米TATB在短脉冲加载下的炸药/窗口界面粒子速度,对亚微米TATB的反应区结构进行了探讨。亚微米TATB是通过重结晶-气流粉碎的方法制备的,平均颗粒度0.58μm。 相似文献
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介绍并分析了Campbell 等人及其他作者研究非均匀炸药冲击起爆和起爆后行为所获得的实验结果,但不涉及其冲击起爆条件。足够强的冲击波进入非均匀炸药后,爆轰将瞬时(指不经过感应时间)且直接(指不经过其他过程,如爆燃)被引发;非均匀炸药起爆后,其中传播的自始至终是一个不断增长的爆轰波,直至发展为正常爆轰,整个过程都是爆轰的增长(新定义)过程。不存在由反应冲击波不断增长并转变为爆轰波的所谓向爆轰的增长。所谓向爆轰的增长,实际上是爆轰的增长(按新定义)的初期;Craig原定义的爆轰的增长,实际上是爆轰的增长(按新定义)的后期;而所谓反应冲击波,实际上是增长中的初期爆轰波。爆轰的增长(按新定义)是所有猛炸药的特性,炸药反应不充分并逐渐趋于充分是爆轰的增长的化学机制。 相似文献
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CTVD格式数值计算非均质炸药爆轰问题 总被引:3,自引:0,他引:3
将高分辨率激波捕捉格式CTVD格式拓展应用到非均质炸药爆轰的数值模拟问题.增加了化学反应率控制方程,引入Lee-Tarver点火成长模型,未反应的固体炸药和化学反应气体产物都使用JWL形式状态方程.数值模拟了非均质固体炸药PBX-9404和TATB的冲击起爆问题.获得了较高的爆轰波分辨率和光滑解区的数值精度,对具有复杂物态方程形式的固体炸药爆轰问题,CTVD格式具有简单实用、高效和高分辨的特点. 相似文献
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针对爆轰波在炸药-金属界面上折射时由实验获得的金属折射冲击波压力与经典爆轰波极曲线理论预测的压力存在显著差异这一问题, 本文展开了进一步的理论和数值模拟分析研究. 首先通过分析指出经典爆轰波极曲线理论的缺陷, 并对爆轰波极曲线理论进行了改进, 改进爆轰波极曲线理论给出了炸药爆轰波折射类型以及折射冲击作用点处的压力值. 然后发展了一个基于次特征理论来数值求解爆轰反应流动控制方程的二阶中心型Lagrange方法, 并数值模拟了一个典型的炸药爆轰波折射实验. 改进爆轰波极曲线理论和数值模拟分析结果表明, 爆轰波折射类型有三种:反射冲击波的正规折射、带Mach反射的非正规折射、无反射波的正规折射, 并且金属折射冲击波压力值随入射角增大而单调减小. 相似文献
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基于Kim的弹粘塑性单球壳塌缩模型,考虑PBX炸药中的粘结剂效应,假设炸药和粘结剂均为弹粘塑性材料,建立了弹粘塑性双球壳塌缩热点反应模型,给出了炸药球壳在冲击压力作用下的速度、应变、温度和化学反应速率的时空分布,以及新的热点反应速率理论表达式。把新的热点反应项与Kim的低压下慢反应项和张震宇提出的高压反应速率方程相结合,得到了新的冲击起爆三项式细观反应速率模型。把该模型加入DYNA2D中,模拟了PBX-9501炸药的一维冲击起爆过程,结果表明:该模型除了可以解释炸药颗粒度和孔隙度的影响外,还可以较好地描述粘结剂强度和含量对PBX炸药冲击起爆感度的影响。 相似文献
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HL-10炸药是一种以RDX为基的含铝炸药,为了研究该炸药在子弹或金属破片撞击作用下的安全性,利用12.7 mm机枪法对钢壳包覆的柱形HL-10装药进行了枪击试验,试验结果表明,炸药没有发生燃烧或爆轰现象,由此可定义该炸药的枪击感度试验反应等级为1级。建立了炸药枪击试验的计算模型和数值计算方法,对子弹撞击和穿透炸药过程进行了三维数值模拟计算,计算结果与试验结果相符,分析了子弹速度对HL-10炸药枪击感度的影响,其结果可为炸药安全性评价分析提供理论根据。为了进一步验证计算模型和方法,对美国的PBX-9404炸药的枪击作用过程进行了计算分析,结果表明,PBX-9404炸药在枪击作用下发生了完全爆轰反应,与Neff等人的试验结果相吻合。 相似文献
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为了确定空气间隙和金属隔层对冲击起爆的影响,采用火炮加载蓝宝石飞片冲击起爆Φ50 mm×30 mm的A型炸药,产生的冲击波通过空气间隙和金属隔层起爆Φ50 mm的台阶型B型炸药。在B型炸药的后界面粘贴镀膜氟化锂(LiF)窗口,使用光子多普勒测速仪(PDV)测量金属和B型炸药的后界面速度,进而计算得到金属和B型炸药的冲击波透射压力,再利用阻抗匹配计算得到金属和B型炸药的入射压力。结果表明:传爆药和金属隔层间的空气间隙使冲击压缩过程转变为准等熵压缩和冲击压缩两个过程,同时使冲击波的幅值减小;确定了金属隔层厚度为5 mm时冲击波压力的衰减范围;当使用A型炸药作为传爆药,空气间隙为0.3 mm,金属隔层厚度为5 mm时,B型炸药在7~10 mm之间开始反应。 相似文献
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为研究A型钝感炸药冲击起爆反应演化过程,进行了火炮驱动蓝宝石飞片的一维平面冲击实验。实验中采用光子多普勒测速仪(Photonic Doppler velocimetry,PDV)技术测量冲击起爆后台阶型炸药的粒子速度。在炸药不同厚度台阶的后界面固定镀铝膜的楔形氟化锂(LiF)窗口,利用阻抗匹配将PDV测量的LiF窗口波后粒子速度转化为炸药样品波后粒子速度。比较组合式电磁粒子速度计和PDV两种测速技术,结果表明,相较于组合式电磁粒子速度计,PDV测量的粒子精度更高。简要分析了PDV测速探头角度、探头孔径、窗口折射率等影响,得到PDV测速的相对不确定度小于1%。 相似文献
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James Rosario Gambino Donald William Schwendeman 《Combustion Theory and Modelling》2016,20(6):1088-1117
The dynamics of detonation in a granular explosive following a piston impact is examined computationally for a two-phase model. Different choices are considered for equations of state and reaction rate. Of special interest is the behaviour of the run-to-detonation distance as a function of the initial porosity of the explosive, for which new experimental information has recently become available. It is found that this response can vary both qualitatively and quantitatively depending upon the constitutive input to the model. Computations based upon up-to-date equation-of-state and reaction-rate information for the explosive PBX-9501 show that the response of the run-to-detonation distance as a function of the initial porosity is in the shape of an inverted U, which is in qualitative agreement with the latest experiments. Mechanisms responsible for this behaviour are identified. 相似文献
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C. M. Tarver J. W. Forbes P. A. Urtiew 《Russian Journal of Physical Chemistry B, Focus on Physics》2007,1(1):39-45
This paper discusses the Nonequilibrium Zeldovich-von Neumann-Doring (NEZND) theory of self-sustaining detonation waves and
the Ignition and Growth reactive flow model of shock initiation and detonation wave propagation in solid explosives. The NEZND
theory identified the nonequilibrium excitation processes that precede and follow the exothermic decomposition of a large
high explosive molecule into several small reaction product molecules. The thermal energy deposited by the leading shock wave
must be distributed to the vibrational modes of the explosive molecule before chemical reactions can occur. The induction
time for the onset of the initial endothermic reactions can be calculated using high pressure-high temperature transition
state theory. Since the chemical energy is released well behind the leading shock front of a detonation wave, a physical mechanism
is required for this chemical energy to reinforce the leading shock front and maintain its overall constant velocity. This
mechanism is the amplification of pressure wavelets in the reaction zone by the process of de-excitation of the initially
highly vibrationally excited reaction product molecules. This process leads to the development of the three-dimensional structure
of detonation waves observed for all explosives. For practical predictions of shock initiation and detonation in hydrodynamic
codes, phenomenological reactive flow models have been developed. The Ignition and Growth reactive flow model of shock initiation
and detonation in solid explosives has been very successful in describing the overall flow measured by embedded gauges and
laser interferometry. This reactive flow model uses pressure and compression dependent reaction rates, because time-resolved
experimental temperature data is not yet available. Since all chemical reaction rates are ultimately controlled by temperature,
the next generation of reactive flow models will use temperature dependent reaction rates. Progress on a statistical hot spot
ignition and growth reactive flow model with multistep Arrhenius chemical reaction pathways is discussed.
The text was submitted by the authors in English. 相似文献
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A. V. Utkin V. M. Mochalova S. I. Torunov 《Russian Journal of Physical Chemistry B, Focus on Physics》2011,5(3):513-518
An experimental study of the detonation parameters and structure of the reaction zone for liquid high explosives (HEs), such
as bis(2-fluoro-2,2-dinitroethyl)formal (FEFO), tetranitromethane (TNM), and nitromethane (NM) is performed. For each of these
HEs, the time corresponding to the position of the Chapman-Jouguet point is determined: for FEFO, from experiments conducted
at different charge diameters (≈300 ns); for TNM, at a fixed diameter but at different lengths (≈200 ns); and for NM, at the
same diameter and length of the shell, but with detonation being initiated by different HE charge (≈50 ns). The particle velocity
and pressure at the Chapman-Jouguet point for these explosives were measured. For TNM and NM, the dependence of the detonation
velocity on the charge diameter was obtained 相似文献