Investigation of shear layer growth influenced by shock waves in a scramjet

The growth of the boundary layer and mixing layer influenced by shock waves in a model scramjet engine is numerically investigated to understand the physics involved in boundary/mixing layers and compression/expansion waves in supersonic flow. The qualitative and quantitative agreements are found between the experimental data and the simulation results, which validates that calculations are reasonable. The displacement thickness of the boundary layer is carefully examined in comparison with shock waves in the scramjet. The thickness of the mixing layer formed by the Mach 2.3 hydrogen jet, and the Mach 2.0 airstream is also calculated and plotted over the channel length to assess the impact of shock waves on its development. It is confirmed that the boundary layer grows along the wall, and it locally separates from the surface due to the adverse pressure gradient when the shock wave impinges on the boundary layer. The mixing layer thickness increases wave-likely over the channel length. This is due to the shock waves that reflect on the channel walls as they travel downstream in the chamber.