膛口流场动力学过程数值研究

采用基于ALE方法的动网格及嵌入网格技术，运用有限体积方法，结合二阶精度Roe格式，对弹丸由高压气体驱动从静止状态加速至超音速，射出膛口到完全飞离初始流场的整个过程进行了数值模拟．根据数值结果，详细讨论了初始流场、火药燃气流场的形成与发展以及与弹丸的耦合和相互作用过程，揭示了在这一变化过程中激波与激波、激波与漩涡、激波与弹丸等的相互作用以及激波衍射、聚焦等对弹丸加速的影响．

Numerical Investigations on the Dynamic Process of the Muzzle Flow

The integrative process of the quiescent projectile accelerated by high-pressure gas to shoot out at a supersonic speed and fly out of the range of precursor flow field was simulated numerically. The calculation method was based on ALE equations and second-order precision Roe method adopting chimera grids and dynamic mesh. From the predicted results, the coupling and interaction among the precursor flow field, propellant gas flow field and high-speed projectile were discussed in detail. And the shock-vortex interaction, shockwave reflection, shock-projectile interaction together with shock diffraction and shock focusing were demonstrated clearly to explain the effect on the acceleration of the projectile.