基于ALE方程的动网格膛口流场数值研究

基于ALE(Arbitrary Lagrangian-Eulerian Equation)方程的有限体积法,采用高精度Roe方法及结构化动网格,利用嵌入网格技术及动边界条件,对弹丸由膛内高压气体推动射出到完全飞高初始流场的整个过程进行了数值模拟.根据数值结果绘制了膛口流场密度和压力分布的时序图,形象地再现了膛口流场中初始激波、弓形激波及膛口冲击波,以及接触闻断、漩涡和剪切层等的动力学发展过程.结果基本反映了膛口流场的典型变化特征,为进一步研究真实膛口流场(如带化学反应、湍流等)奠定了基础.

Numerical investigation on the muzzle flow with dynamic mesh based on ALE equation

In this paper the finite volume method of Arbitrary Lagrangian-Eulerian equation(ALE) and high precise Roe scheme was adopted by using structured dynamic mesh,chimera method and moving boundary condition.The full process of the projectile driven by high pressure gas inside the gun to shoot out and penetrate through the flow field disturbed by precursor shock was simulated numerically.The density and pressure distributions of the muzzle flow were plotted sequently based on the predicted results,which demonstrated visually the production and development of the precursor shock wave,bow shock wave,muzzle blast wave,and the contact surfaces,vortex and shear layer near the muzzle.Results indicated that the typical characteristics of the muzzle flow were captured basically and the numerical method adopted here was feasible.This work lays on the foundation of our further investigation on the real muzzle flow,such as considering the chemical reaction,turbulence,etc.