起爆方式对聚能射流性能影响的数值分析

Numerical Simulation of Shaped Charge Jet Formation Under Different Ways of Initiation

应用LS-DYNA有限元程序,采用ALE方法对聚能装药在点起爆、面起爆、正向环形起爆和逆向环形起爆等不同起爆方式下的射流形成过程进行了三维数值模拟.计算结果表明,起爆方式对射流性能有着重要的影响;不同的起爆方式在装药中产生不同的爆轰波形,当爆轰波波形与药型罩外表面越接近时,罩微元的压垮速度越高,导致射流头部速度越高;环形起爆形成的射流头部速度高于面起爆的,面起爆高于点起爆的,并且随着起爆直径的增大,面起爆与环形起爆所形成的射流头部速度逐渐增大.

LS-DYNA finite element code is used to simulate the formation processes of shaped charge jet under point initiation, plane initiation, direct and inverse annular initiation. Calculated results such as jet tip velocity and diameter are obtained. The results are in good agreement with experimental data, which proves that the model established in the paper is reliable. By analyzing the results, it suggests that ways of initiation have great influence on jet performance. Different ways of initiation produce different shapes of detonation wave, and the jet performances prove to be better when the wave shape better matches the outside shape of the liner. Hence, jet tip velocity produced by direct annular initiation is higher than that of plane initiation, and plane initiation higher than point initiation. It is also concluded that the jet tip velocity of plane and annular initiation increases as the initiation radius increases.