Shock-Shock interaction and Shock-Wave/Boundary Layer Interaction (SWBLI) is a complex flow phenomenon which commonly occurs in all high- speed flow problems. SWBLI gets more complex, when massive amount of kinetic energy converts to internal energy, which triggers both thermal and chemical non-equilibrium effects inside the flow field especially at the boundary layer. Conversion of huge amount of kinetic energy to internal energy inside the boundary layer further excites vibrational energy modes including mild chemical dissociation of oxygen. Consequently, accurate prediction of shock-shock and shock-wave/boundary layer interaction is very crucial to design hypervelocity vehicles. In this present study, numerical simulation of Shock-Wave/Boundary Layer Interaction over a hollow cylinder flare body has been carried out. Air is assumed to behave as an eleven species mixture \(\left( {{\text{N}}_{2} ,{\text{N}}_{2}^{ + } ,{\text{O}}_{2} ,{\text{O}}_{2}^{ + } ,{\text{NO}},{\text{NO}}^{ + } ,{\text{N}},{\text{N}}^{ + } ,{\text{O}},{\text{O}}^{ + } \,{\text{and e}}} \right)\) . The flow is assumed to be laminar and both thermally and chemically non-equilibrium in nature. Time-averaged wall heat flux and pressure from 0 to 300 μs shows good agreement with the experimental Run 3 data conducted by MacLean et al. (Measurements of real gas effects on regions of laminar shock wave/boundary layer interaction in hypervelocity flows, 2014). Unsteady Compressible Reacting Navier–Stokes Fourier equations are solved by hy2Foam solver (Casseau in An open-source CFD solver for planetary entry, 2017) in OpenFOAM platform.