针对激波诱导物体运动的二维动力学模型,比较了采用流动定常、结合非定常弹道方程的所谓“准定常”计算方法和非结构动网格计算方法,通过流场和运动特性分析,指出发展有相对运动的非定常流动模拟方法的重要性;另外采用修正弹簧近似和局部重构的非结构动网格技术,耦合求解Euler方程及6DOF弹道方程,数值模拟高度H=25km、飞行马赫数Mα=6.0、迎角α=0°状态下火箭抛罩的动力学过程。研究表明,稠密大气层内头罩受到的气动力比惯性力大几个数量级,导致头罩的运动特性完全由气动力控制。分离过程中,头罩和火箭头部之间的气动干扰在时间和空间上都表现出强烈的非线性特征,头罩姿态变化剧烈。本文还对分离过程中部分位置上的流场进行定常模拟,比较了定常和非定常的气动力,所得结论对于分析地面风洞可控轨迹系统(CTS)试验具有指导意义。
The motion of a sphere-cylinder induced by shock wave is firstly numerically simulated in this article. Comparison the two methods, which are the quasi-steady simulation method that coupled with ballistic equation and the dynamic unstructured method, show great importance to develop the numerical method for moving bound-arise. The improved spring analogy and local mesh generation method coupled with Euler solver and 6DOF ballistic equation is then applied to simulate the behavior of fairing separation at 25km, in Mα = 6.0 and α = 0°. It can be concluded that the trajectory is mostly determined by aerodynamic forces; the interference between the rocket and fairing, which appears nonlinear feature, has significant effects on fairing attitude. At last, several steady flow fields in different stage of separation trajectory are simulated. The result of comparison between steady aerodynamic forces and unsteady ones gives useful advice to analyze CTS experiment.