高超声速复杂外形热流的NND有限元数值计算方法研究

有限元法是一种加权积分的方法,这个特点和权函数的特性使得有限元法在计算诸如热流(与温度的一阶导数相关)等物理量时有其内在的优越性.本文研究了高超声速复杂外形热流的NND有限元数值计算方法,并对高超声速球钝锥外形和带翼飞行器外形的绕流进行了数值模拟,算例结果令人满意.

The study of heat transfer rate around complicated configurations in hypersonic flows using NND finite-element method

Finite element method is a weight integration approach,and it is more approximate to predict a comparatively accurate value of heating rate on the body surface than finite difference method.In this paper,the authors investigated the calculation of heat flux over complex configurations by means of the NND finite element method.In order to achieve high (resolution) computations near the strong discontinuities without spurious fluctuations,a explicit non-oscillatory non-free-parameter dissipative finite element scheme is proposed,by using the flux splitting technique and applying the idea of the NND scheme in finite difference method.Collected mass technique was adopted to treat with left item in equations to avoid solving large-scale sparseness matrix.The algebraic equations for heat flux can be gotten by integrating the energy equations,and then more resonable values in averaging sense can be obtained.The numerical simulation results over hypersonic vehicles with blunt nose configuration and vehichles with flaps are satisfactory.