Numerical Simulations of Multiple Shock Wave Boundary Layer Interactions

Shock wave boundary layer interactions occur in many aerospace applications, and of particular interest are the interactions occurring in high-speed intakes. The high-speed intakes aim to decelerate the flow with minimum losses using a series of oblique shocks followed by a weak normal shock. Depending on the state of the boundary layer and on the upstream Mach number, multiple shocks can form in the throat of the intake. Often, they are referred to as shock trains, or pseudo-shocks and can have a significant impact on the intake performance. The in-house CFD solver of the University of Glasgow is used here, to investigate an isolated multiple shock interaction and quantify the effect of different non-linear turbulence models. The non-linear models, and their ability to account for the Reynolds stress anisotropy, resolve the corner flows and give favourable agreement with experiments. As a second step, shock train simulations in a geometry more representative of a high-speed intake are performed. Three different pitot intakes are considered and performance metrics based on the total pressure recovery and flow distortion are evaluated at different free-stream conditions. The predicted shock trains are highly asymmetric and the strong sensitivity of the total pressure recovery and flow distortion to the intake geometry is observed to reduce at higher incidence angles