The cavity in supersonic combustor provides a stable flame holding with enhanced mixing. Computational analysis of the flow field associated with the cavity based supersonic combustors is presented. Results are obtained by numerically solving unsteady, compressible, turbulent Navier-Stokes equations, using Unstructured Finite Volume Method (UFVM) incorporating RNG based κ-ε two equation model and time integration using three stage Runge-Kutta method. Reaction is modeled using a simplified two step H 2-air chemistry. The code is validated against standard experimental data. The extend to which fuel injected upstream of the cavity, mixes with the cross flow, will vary as the aft wall angle has a vital role in deciding the nature of shear layer formed in the cavity region.