三维驻点可压缩边界层计算

The Calculation of Compressible Boundary Layer at Three-Dimensional Stagnation Point

本文对三维物体的驻点可压缩边界层问题进行计算研究。通过引入自动满足连续方程的两分量矢量函数和适当的坐标变换后所得到的边界层方程组虽然有了很大的简化,但是它的求解仍是一个八阶非线性边值问题。文中采用高效率的分步计算方法于边界层计算中,使得系数块矩阵从8×8阶降为三组2×2阶,这样大大简化了方程和减少了计算机时。本文还研究了一些重要参数,例如主速度梯度比,Prandtl数以及与壁面热交换有关的参数等对驻点边界层流场的影响。各种算例的结果显示,计算值与有关文献的完全一致。

The problem of compressible boundary layer at the stagnation point of a three-dimen-sional body is investigated computationally in this paper. Although boundary layer equa tions are simplified drastically by introducing a two-component vector potential satisfying the continuity equations and appropriate coodinate transformation,it is difficult to solve an eighth order system of nonlinear differential equations. A step computational method, which is highly efficient,is used to compute boundary layer equations. By this method coef-ficient block matrixes 8×8 are reduced into 2×2 of three groups,equations are simplified, and the computer time is reduced. The effect of important paramenters ,such as the ratio of principal velocity gradients ,Prandtl number and relevent paramenter with heat transfer at the wall,on the flowfield is studied specially by different examples.It is shown that com-puted results are quite consistent with those presented in other Refereces.