Computational Fluid Dynamics (CFD) simulations have been performed over a blunt cone configuration with and without lateral sonic jet injected into hypersonic laminar flow at Mach 8.1. The comparison of pressure ratio indicates good match with the experimental results for no jet case. The simulation with sonic jet results in a complex flow field interactions like shock-boundary layer, shock-shock interactions, barrel shock, Mach disk, primary and secondary separations ahead of the jet etc.,. The comparison of pressure ratio indicates over-prediction of the plateau pressure rise and under prediction of the pressure rise due to the detached shock. The empirical estimates of separation distance, detached shock standoff distance, plateau pressure and jet penetration height matches well with the present CFD results.