活性破片飞散特性及毁伤效应研究

为了掌握活性破片的空间飞散特性及毁伤效能,采用数值仿真与试验相结合的方法研究了某预制活性破片战斗部在爆炸作用下的飞散特性,得到了活性破片的空间分布和初始速度分布参数的有关数据,分析了活性破片对靶板的毁伤规律.结果表明:活性破片战斗部在起爆300 μs后,70％的活性破片速度分布在1 500～2 000 m/s;50％的...     

预制破片侵彻靶板临界跳飞角变化规律

为研究预制破片侵彻靶板的临界跳飞角变化规律,采用数值仿真的方法对预制破片侵彻靶板的临界跳飞角变化规律进行分析.利用LS-DYNA有限元仿真软件,建立了不同形状预制破片侵彻靶板的仿真模型,通过与试验结果相对比的方式验证了模型的可信性.分析了破片形状、破片形状比例系数、破片入射速度和靶板厚度对临界跳飞角的影响规律.分析结果表明:在相同条件下,破片临界跳飞角按照圆柱形、方形和球形预制破片的顺序依次减小,随着破片入射速度和破片形状比例系数的增大而增大,并在一定范围内随着靶板厚度的增加而减小.     

榴弹模拟弹综合威力分析

榴弹作为打击空中目标的弹种之一,其破片与冲击波威力是评价毁伤能力的重要一环。参考意大利奥托·梅莱拉127 mm榴弹,设计榴弹模拟弹,分析其综合威力。采用实验、数值仿真与经验公式相结合的方法,分析破片速度、破片空间分布规律和冲击波超压。实验结果表明,榴弹模拟弹飞散方向角为93.67°,飞散角为65.42°,破片初速为1 451 m/s。仿真和计算结果表明,飞散角的理论计算值与实验值相对差较小;破片速度理论值与实验值相对差不超过20%;冲击波超压理论值、仿真值与实验值相对差不超过15%。     

半预制破片PELE弹丸对武装直升机毁伤效能

为研究半预制破片PELE弹丸对武装直升机的毁伤效能,选取代表性的阿帕奇武装直升机为研究对象,建立了阿帕奇武装直升机关键部件驾驶舱和发动机舱的等效模型,在此基础上应用ANSYS/LS-DYNA就半预制破片PELE弹丸对阿帕奇武装直升机的毁伤效能进行了数值分析.结果表明:半预制破片PELE弹丸能有效穿透阿帕奇武装直升机的防护装甲,在穿透防护靶后弹丸壳体大面积碎裂,产生大量具有较高轴向剩余速度和一定径向飞散速度的破片,形成一个大面积的破片场,这些破片及弹丸剩余部分可对武装直升机内部人员及仪器设备造成有效毁伤,极大地增强了PELE弹丸的毁伤效能.     

钨合金(碳化钨)柱形预制破片战斗部对均质钢甲的毁伤效能分析

针对现代战争的需要,特别是对战场轻型装甲的攻击需要,基于预制破片技术,以柱形杆(钨合金)预制破片为对象建立物理模型,对其破片尺寸、装药形式及尺寸的相互关系进行分析,进而通过引入TBM战斗部设计的关系式对所建模型的破片进行速度预报,依照该速度按照侵彻理论推算其对均质钢甲的毁伤效能。结合分析结果指出了柱形杆(钨合金)预制破片战斗部在攻击均制钢甲方面的优点。     

随动定向战斗部破片飞散特性研究

针对防空导弹常规破片式杀伤战斗部使用中存在能量利用率低的缺陷,提出采用随动定向战斗部的观点。建立随动定向战斗部的破片动态飞散区和飞散速度的计算模型,采用数值解析方法,解决在复杂弹目交会条件下破片的飞散区域与打击速度的计算问题．并用MATLAB软件对建立的模型进行验证,得出仿真结果与实际结果一致,这表明模型是合理、正确的。     

圆柱形装药驱动轴向预制破片飞散特性

为了增强柱形战斗部轴向威力,在无壳柱形战斗部底面布置单层离散的预制破片。开展圆柱形TNT装药驱动轴向预制破片飞散试验,获得预制破片的最大初速、飞散角等特征参数;运用LS-DYNA软件对装药驱动预制破片过程进行数值模拟,阐述预制破片群飞散过程;对装药驱动整体平板理论计算公式进行改进,获得预制破片的最大初速。结果表明:破片初速理论计算结果、数值计算结果和试验结果吻合良好;随着与装药底部中心距离的加大,破片初速、径向飞散角分别近似呈“抛物线”减小、增大;试验实测、理论计算得到的破片最大初速值超过2500 m/s,试验实测的径向飞散角最大约为22°,而周向飞散角则普遍较小,均值在5°以内。     

某预制破片弹丸穿甲威力研究

介绍了战斗部预知破片弹丸所针对的目标,给出了高速运动弹丸对目标的穿甲作用理论以及理论计算方法,并给出了计算结果;同时通过有限元分析方法在有限元分析软件中建立了弹丸对靶板侵彻的仿真计算模型并进行了计算。计算结果表明：预制破片弹丸所具备的威力不但能够侵彻给定的装甲目标,对装甲目标内部设施具有二次毁伤的效果。     

提高反低空高速目标引战配合效率的一种方法

针对未考虑导弹战斗部破片速度衰减的引信自适应模型的缺点,引入破片相对目标的飞行轨迹描述方程,建立了破片速度衰减对飞散方向影响条件下的引信自适应调整模型.通过两种模型的计算机仿真对比分析,验证了新模型在提高导弹射击高速、超低空目标时的引战配合效率方面,比原模型具有明显的优势.     

地空导弹对地面的附带损伤问题研究

研究了地空导弹爆炸时战斗部破片对地面人员附带损伤的问题,选取了破片对人体的杀伤准则,通过分析破片的空中运动特性,对导弹战斗部爆炸时的破片飞散规律进行了探讨,建立了破片散布的数学模型,并在典型的给定计算条件下进行了仿真分析.仿真结果表明,地空导弹在不同高度爆炸时,可计算出对地面人员的有效杀伤破片数量、破片杀伤面积和平均密度以及导弹的安全高度.     

Numerical study on the case effect of a bomb air explosion

When considering the bomb explosion damage effect, the air shock wave and high-speed fragments of the bomb case are two major threats. In experiments, the air shock wave was studied by the bare ex-plosives superseding the real cased bomb; in contrast, the bomb case influence was ignored to reduce risk. The air explosion simulations of the MK84 warhead with and without the case were conducted. The numerical simulation results showed that the bomb case significantly influenced the shock wave generated by the bomb: the spatial distribution of shock wave in the near field changed, and the peak value of shock wave was reduced. Breakage of the case and kinetic energy of the fragmentation consumed 3 and 38% of the explosion energy, respectively. The increasing factors of the peak over-pressure induced by the bare explosive on the ground and in the air were 1.43-3.04 and 1.37-1.57, respectively. Four typical stages of case breakage were defined. The mass distribution of the fragments follows the Mott distribution. The initial velocity distribution of the fragments agreed well with the Gurney equation.     

Real-time calculation of fragment velocity for cylindrical warheads

To simulate explosion fragments, it is necessary to predict many variables such as fragment velocity, size distribution and projection angle. For active protection systems these predictions need to be made very quickly, before the weapon hits the target. Fast predictions also need to be made in real time simulations when the impact of many different computer models need to be assessed. The research presented in this paper focuses on creating a fast and accurate estimate of one of these variables - the initial fragment velocity. The Gurney equation was the first equation to calculate initial fragment velocity. This equation, sometimes with modifications, is still used today where finite element analysis or complex mathematical approaches are considered too computationally expensive. This paper enhances and improves Breech’s two-dimensional Gurney equation using available empirical data and the principals of conservation of momentum and energy. The results are computationally quick, providing improved accuracy for estimating initial fragment velocity. This will allow the developed model to be available for real-time simulation and fast computation, with improved accuracy when compared to existing approaches.     

A novel method for determination of lethal radius for high-explosive artillery projectiles

A new model has been defined that enables the estimation of the lethal radius (radius of efficiency) of HE (High Explosive) artillery projectiles against human targets. The model is made of several modules: CAD (Computer Aided Design) modeling, fragment mass distribution estimation, fragment initial velocity prediction, fragment trajectory calculation, effective fragment density estimation, and high explosive projectile lethal radius estimation. The results were compared with the experimental results obtained based on tests in the arena used in our country, and the agreement of the results was good. This model can be used in any terminal-ballistics scenario for high explosive projectiles since it is general, para-metric, fast and relatively easy to implement.     

转速对动态旋流器流场影响的数值分析

根据计算流体力学方法,对采用不同转速的动态旋流器流场进行数值模拟,深入分析了转速对动态旋流器切向速度、静压以及湍动能的影响。计算采用雷诺应力模型和混合物模型。结果表明:转速对动态旋流器切向速度和静压影响非常大,不但影响其数值大小,对其分布趋势也产生明显影响;转速对动态旋流器湍动能的影响主要集中在旋转栅附近,在转筒后半段转速对湍动能的影响明显弱化,适当提高转速甚至有抑制湍流的作用。     

Effect of microstructure on short pulse duration shock initiation of TATB and initial response mechanism

Micro-TATB particles with different sizes and 3D nanoporous TATB architectures with different specific surface areas were prepared through recrystallization to study short pulse duration shock initiation properties by electric gun technology. For micro-TATB, the initiation threshold significantly decreases with TATB average size ranging from 79.7 μm to 0.5 μm. For 3D nanoporous TATB architecture, the initiation threshold decreases and then increases with specific surface areas increased from 9.6 m²/g to 36.2 m²/g. The lowest initiation thresholds are obtained for the micro-TATB with average sizes of 1.3 μm and 0.5 μm, and 3D nanoporous TATB architecture with specific surface area of 22.4 m²/g. The shock initiation thresholds of micro-TATB and 3D nanoporous TATB architectures show significantly decreases with the porosity increased. The decomposition reaction and thermal conductivity properties were further investigated to understand the initial response mechanism. High porosity provides more collapse sites to generate high temperature for formation of hot spots. The low thermal conductivity and decomposition temperature could enhance the formation and ignition of the hot spots, and initial decomposition reaction of TATB. The effect of the decomposition temperature is higher than that of the thermal conductivity on the shock initiation properties. The enhanced decomposition reaction could promote energy release and transfer process from the ignition to the combustion. This work offers a new insight to understand the effects of microstructure on the shock initiation properties and the initial response mechanism of TATB.     

Experimental studies of explosion energy output with different igniter mass

For study the energy output law of cylindrical charge with shell induced by different input energies, four different black powder masses were selected to ignite the main charge. Fragmentation degree of the shell was qualitatively analyzed by the area of holes on the witness plate and the recovered fragments mass. Through theoretical analysis, established the functional relationship between the average mass of fragments and the relative energy output of warhead, obtained how the relative energy output of charge changed with different initial energy input. The results showed that the change of input energy could lead to obvious variation in fragment characteristics, and could also control the output of charge. When the igniter mass increases from 1.55 g to 5.00 g, the relative energy output of the charge increases by 26.28%. Excessive initial input energy will destroy the shell confine in advance, resulting in a decrease in the relative energy output of charge.     

利用MSC/DYTRAN程序仿真分析导弹战斗部立方体破片的侵彻威力

对反辐射导弹的破片杀伤战斗部中较为常见的立方体破片的 3种典型姿态侵彻 (尖端、棱边及正面侵彻 ) 4mm厚 94 5钢的侵彻过程进行仿真数值计算 .通过仿真计算 ,结合实验结果比较 ,得出结论 :不同初始侵彻姿态的立方体破片在侵彻过程中 ,由于旋转角速度的作用及稳定性的要求 ,破片的侵彻姿态将趋于正面侵彻 .不同姿态的侵彻 ,侵彻威力相差不大     

Experimental study on explosion dispersion process of a multi-layer composite charge under different initiation modes

The influence of initiation modes on the explosive dispersion process of the multi-layer composite charge (MCC) was studied. Overpressure sensors and high-speed photography system were used to investigate the energy release process of an MCC with a specific structure. The shock wave pressure and explosive dispersion characteristics of the MCC under different initiation modes were compared. The forming and expanding process of the shock wave of the composite charge under different initiation modes was determined. The separation position of the shock wave and fireball interface was determined. The calculation formulas of the shock radius and overpressure of the composite charge are presented. The radius of the shock wave of the composite charge was significantly affected by the initiation mode. Moreover, the development process of the composite explosive fireball under different initiation modes was analyzed, the variation rules of the composite charge dispersion radius and fireball dispersion velocity with time were obtained under the different initiation modes, the explosion energy release rate of composite charge under simultaneous initiation modes was the highest, and the peak overpressure under the simultaneous initiation mode was 1.61 times that of central single-point initiation.     

空气深度预冷组合循环发动机吸气式模态建模及性能分析

针对空气深度预冷组合循环发动机——协同吸气式火箭发动机(Synergistic Air-Breathing Rocket Engine,SABRE),采用部件法对其进行建模,匹配计算得到吸气式模态下飞行走廊内其性能参数变化规律,并研究其高度速度特性。计算模型可信度较高,推力误差小于6%,能够较为准确地模拟SABRE吸气式模态的性能参数。结果表明:SABRE兼具火箭发动机大推力和航空发动机高比冲的特点,吸气式模态下比冲介于21 300~27 380 m/s,随着高度速度的增大,其推力比冲先增大后减小;SABRE利用预冷器将入口空气温度降低,可使其空域速域拓宽至25 km、5Ma,满足高超声速飞行的动力需求;发动机速度下限由压气机最大流量决定,速度上限则由氦气回路减压器工作限制条件决定。