斜激波串非对称特性研究

Asymmetry of Oblique Shock Train

关键词:  隔离段  斜激波串  非对称性  建模分析  数值仿真

Key words:  Isolator  Oblique shock train  Asymmetry  Modeling analysis  Numerical simulation

摘要:

针对马赫数2.0~4.0均匀来流条件下斜激波串流场的非对称特征开展了数值仿真研究和建模分析。通过改变出口背压和入口马赫数条件分析了不同状态的激波串结构形态，利用前缘激波起始点位置差定义了激波串非对称度系数，分析得到了激波串的非对称度系数变化规律。结果表明，斜激波串出现非对称现象时，前缘激波起始点位置和前缘激波角度均不相等。任何马赫数条件下激波串的非对称度系数都存在极限值，可以通过自由相互作用理论和激波关系式计算得到。斜激波串的非对称度系数总体上与马赫数平方和壁面摩擦系数乘积成正比。

Abstract:

Numerical studies and modelling analysis are performed to investigate the asymmetry phenomenon of oblique shock train with incoming Mach number ranging from 2.0 to 4.0. The structural morphology of shock train in different states are analyzed by changing outlet back pressure and inlet Mach number. The difference of the starting point of leading edge shocks is used for defining the asymmetry coefficient of shock train. And the change law of the asymmetry coefficient of shock train is obtained. The numerical results show that the starting point and angle of leading edge shocks are both different when asymmetric phenomenon of oblique shock train appears. There is a limit value for the asymmetry coefficient of shock train at any Mach number， which can be calculated by free interaction theory and shock wave relation. The asymmetry coefficient of oblique shock train is generally proportional to the product of the square of Mach number and the wall friction coefficient.