Identification of coherent structures in a supersonic flow past backward facing step

The present work reports the physics of turbulent supersonic flow over backward facing step (BFS) using Large Eddy simulation (LES) methodology where the dynamic Smagorinsky model is used for SGS modeling. Proper Orthogonal Decomposition is employed to identify the coherent structures present in the flow. The mean data obtained through computation is validated against experimental result which is found to be in good agreement. The POD analysis reveals the presence of coherent structures. The first and secondmode confirms the vortical structure near the step as well as along the shear layer in downstream region. The dominating coherent structures are the ones observed within shear layer and in the vicinity of step.