高压弹射装置内弹道二维模型及发射腔内流场特性分析

高压弹射装置中火药先燃烧积聚成高压气体,后瞬间打开,弹射弹丸攻击目标。为了掌握这一过程中发射腔内流场的复杂变化,建立了高压弹射装置内弹道二维气相模型,采用RungerKutta算法和Mac Cormark差分格式耦合方法进行数值模拟,并将计算所得的压力曲线与试验结果进行对比,验证了数值计算的可靠性。进一步根据计算得到发射腔内气体压力、速度等参量的分布情况,分析发射腔内的流场特性。结果表明,弹射关键阶段在弹丸启动的较短时间内,高压气体大小和分布是影响弹丸弹射效果的直接因素。

Two-dimensional Interior Ballistics Model of High Pressure Ejection Apparatus and Analysis on the Characteristics of Flow Field in Launching Chamber

High pressure accumulated by propellant burning in high pressure ejecting apparatus makes the chamber open instantly and eject a projectile to a target. In order to grasp the complex change of gas flow in the launching chamber, a two-dimensional interior ballistics model is established and simulated by Runger-Kutta and MacCormark schemes. The calculated pressure results are reliable by comparison with the experimental ones. The flow field characteristics are got through the analysis of the calculated results, such as gas pressure, velocity, etc. The results show that the size and distribution of high pressure gas accumulated at the bottom of the projectile have the direct effects on the ejection performance.