Dynamics of a supersonic flow over a backward/forward-facing step

Abstract

The backward/forward-facing step (BFS/FFS) is one of the canonical geometries in aerospace engineering applications, the flow field over which has attracted extensive attention in the past decades. In a supersonic flow, laminar-to-turbulent transition and shock wave/boundary layer interaction (SWBLI) can occur over these configurations, which considerably affect the performance of aircraft, through, for example, an increase of flight drag and intense localized mechanical loads. In this thesis, a numerical study is carried out to scrutinize the dynamics of a supersonic flow over a backward/forwardfacing step at Ma AE 1.7 and Re±0 AE 13718 using well-resolved large eddy simulations (LES). For the transition aspect, our objective is to determine the transition path and the roles of the instabilities involved in this process. Considering the topic of SWBLI, the main objective is to scrutinize the various unsteady phenomena observed in SWBLI and, in particular, identify the origin of the low-frequency unsteadiness.