The study of high-speed flows is of great importance in the design and manufacture of aerospace vehicles, missiles, and rockets. The flow physics is complex and experimental investigations with full size prototypes are quite expensive. To study such complex flows, there is a need for a numerical test bench that is both robust and customizable. To this end, in this study, a systematic validation of the open source computational fluid dynamics software called OpenFOAM has been undertaken. Numerical simulations of the high-Mach-number supersonic flow in a mixed compression intake in nine different configurations have been carried out. The predictions are seen to compare well with the experimental data reported in the literature. Important features such as the location and strength of oblique shocks and expansion fans are predicted well. The shock-boundary layer interaction for subtle variations in geometric configurations could also be replicated as observed experimentally. The roll up of the boundary layer due to shock interaction over very small time instants could be easily captured, which would be difficult do accomplish experimentally. Although not all permutations and combinations of the parameters have been studied, with the limited study the power of the above mentioned open source software has been established.