起爆方式对聚能射流特性影响数值模拟研究

Numerical Simulation of the Influence of Detonation Modes on Shaped Charge Jet Characteristics

运用LS-DYNA软件对中心点起爆、环形起爆方式下聚能射流成形及引爆覆盖一定厚度平面钢壳装药过程进行数值仿真,研究表明起爆方式对聚能射流性能具有较大影响。底部中心点起爆时,爆轰波周向传播至壳体后反射形成新的波系并向装药轴线方向汇聚碰撞,压力比值是稳定爆轰时的2.6倍,属于正碰撞问题。环形起爆方式的起爆环半径从4 mm增至20 mm过程中,爆轰波碰撞和反射形成的爆压呈增大趋势。装药起爆环半径为20 mm时发生马赫反射现象,爆轰能量高度集中于狭小空间形成局部高压区,压力比值是稳定爆轰时的3.5倍,聚能射流头部速度是中心点起爆的1.28倍,能够冲击引爆覆盖100 mm厚平面钢壳装药。

Numerical simulations were conducted for shaped charge jets formed with the center point detonation and circular detonation modes.The process of the detonation covering a flat steel case with a certain thickness is also simulated.Research shows that detonation modes have a great influence on shaped jet performance.In the case of base center point detonation,the detonation wave propagated in a circumferential manner to the case before being reflected and forming new waves.The new waves collided and gathered at the axis of the charge,their pressure ratio being 2.6 times that of steady detonation.This case belongs to the frontal collision problem.In the case of circular detonation,the detonation ring radius expanded from 4 mm to 20 mm,in the process of which the detonation pressure generated by colliding and reflecting detonation waves registered an increasing trend.Mach reflection occurred when the radius of the charge detonation ring is 20 mm,and the detonation energy is highly concentrated in a narrow space to form a local high pressure area.The pressure ratio was 3.5 times that of steady detonation,and the velocity of the shaped charge jet tip was 1.28 times that of central point initiation,which could impact and detonate the charge covering a flat steel case with a thickness of 100 mm.