DOI: 10.1615/TSFP7
LOW-ORDER MODEL FOR THE LOW-FREQUENCY UNSTEADINESS IN OBLIQUE-SHOCK/TURBULENT-BOUNDARY-LAYER INTERACTIONS
摘要
The interaction between a turbulent supersonic boundary layer and an impinging shock wave is investigated numerically and analytically. The reflected-shock low-frequency motions are well captured even when using a narrow simulation domain, supporting the argument that one underlying key mechanism for the low-frequency shock motions is two dimensional. Based on a two-dimensional approach, a stochastic ordinary differential equation for the low-frequency coupling between the reflected shock and the boundary layer is obtained. The system is closed and applied to a wide range of input parameters. It is argued that the low-frequency shock motions are not necessarily a property of the forcing, either from upstream or downstream of the shock, but are simply an intrinsic property of the coupled dynamical system.