钝锥超声速粘性绕流的隐式推进求解方法研究

A STUDY OF IMPLICIT SPACE-MARCHING METHOD FOR THE SUPERSONIC VISCOUS FLOW OVER THE BLUNT CONE

本文提出了一种新的推进求解方法。通过对模型方程的稳定性分析和钝锥超声速绕流的数值模拟,表明该方法既克服了文献中推进格式步长有下界和稳定性差的不足,也克服了亚声速区压力不好处理的困难。文中建立的一阶、二阶隐式推进格式,稳定性好,推进步长无下界,计算结果的精度较高。

A new technique for handling the pressure gradient in the streamwise momentum equation of parabolized Navier-Stokes equations has been developed to compute the supersonic viscous flow over the bodies using a noniterative, implicit, space-marching finite difference method. The stability conditions for space-marching method using a new technique have been derived from model equations. The stable space-marching schemes without a minimum allowable step size are given. The schemes have been used to compute supersonic flow over axisymme-tric blunt cone. The results of the computations are compared with those from conventional marching methods using other technique for treating the streamwise pressure gradient term. The present technique exhibits the superior capabililies for accurate and stable calculations.