钝体边界层失稳特性分析

Instability analysis of blunt body boundary layers

推导了适合可压缩二维/轴对称边界层的线性抛物化稳定性方程。在法向采用4阶中心格式,流向采用1阶向后差分,对线性抛物化稳定性方程进行离散。通过来流马赫数为4.5的平板与曲面边界层稳定性问题验证了程序的正确性。讨论了来流马赫数6的球钝锥边界层内,扰动波沿端头向下游演化的失稳特性。发现了一种新的失稳机制。

A linear parabolized stability equations（PSE） for two-dimensional/axisymmetric compressible boundary layers is derived.The linear PSE is discretized in both the streamwise and wall normal directions.The discretization in the streamwise direction is the implicit backward first order and,the wall normal direction,fourth order central finite-difference schemes.The program is validated by the stability problem of Mach 4.5 boundary flows of plate and curvous plates.The instability of blunt body boundary layers is discussed.A new mechanism of instability is found.