发射药冲击破碎对埋头弹装药燃烧和内弹道性能影响的数值模拟  

Numerical Simulation of the Effect of Impact Crushing of Propellant Grains on the Combustion and Internal Ballistic of the CTA

作　　者：熊佳敏 陆欣[1] XIONG Jia-min;LU Xin(College of Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学能源与动力工程学院,江苏南京210094

出　　处：《火炸药学报》2023年第4期352-360,共9页Chinese Journal of Explosives & Propellants

摘　　要：为探究药粒冲击破碎现象对埋头弹火炮发射过程产生的影响,忽略火药药粒的差异性与不一致性,根据火药冲击挤压破碎机理,提出一种新的与火药形状相关的理论方法,利用火药形状参数变化模拟药粒破碎过程;埋头弹一维两相流仿真研究中应用此药粒破碎模型,预测发射药粒破碎在点传火过程中对埋头弹内弹道性能的影响,完善埋头弹火炮独特的装药结构以及点火理论基础,增强其发射安全性。通过仿真火药颗粒未发生破碎与发生破碎的模拟结果比较表明,在埋头弹火炮点火异常下,发射过程中膛内局部药粒冲击破碎会使得挤压应力飙升,最大值从25.7MPa升至35.1MPa,上升了36.6%;火药燃面比例显著增大,破碎度最高达5.8;膛压猛增并有可能产生异常压力,最大膛底压力和最大弹底压力分别是未破碎的1.069倍及1.047倍;易引发大振幅的压力波以及波动剧烈的压力波,压力波最大负峰值从-2.6MPa降至-11.0MPa;膛内气固两相运动更为复杂多变,炮口初速由1146m/s增至1163m/s。In order to explore the influence of impact crushing phenomenon of propellant grains during the Cased Telescoped Ammunition(CTA)firing process,the difference and inconsistency of gunpowder grain is ignored,and a new theoretical approach related to the shape of gunpowder is proposed.According to the impact and crushing mechanism of energetic gunpowder,the grain impact crushing process is simulated by using the changes in gunpowder shape parameters.This grain fragmentation model is applied in the simulation of the one-dimensional and two-phase flow simulation of the CTA.The effect of grain fracture on the ballistic performance of the CTA during the ignition process can be predicted,which will improve the unique charge structure and ignition theoretical basis of the CTA and also enhance the launching safety.By comparing the simulation results of simulated gunpowder particles without fragmentation and breakage,it is found that under the abnormal ignition of the CTA,partial crushing grains in the chamber during firing will cause the surge of crushing stress,and the maximum value increases from 25.7MPa to 35.1MPa,with an increase of 36.6%.The proportion of gunpowder combustion surface increases significantly,the degree of fragmentation reaches as high as 5.8.Meanwhile,the breech pressure increases sharply,and the maximum chamber bottom pressure and the maximum bullet bottom pressure is 1.069 times and 1.047 times respectively compared with the normal structure.The high-amplitude and choppy pressure waves are easily generated,and the maximum negative peak of the pressure wave decreases from-2.6MPa to-11.0MPa.The gas-solid two-phase movement in the bore is more complex and changeable,and the muzzle velocity increases from 1146m/s to 1163m/s.

关 键 词：爆炸力学 火药颗粒 冲击挤压 埋头弹火炮 压力波 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O38[理学—流体力学]