Using numerical simulation to investigate the effect of injection configurations over the scramjet performance

Abstract

Achieving combustion in the available residence time by efficient mixing of the injected fuel has been a challenge for scramjet designers since years. Design of the injection configuration do affect the patterns of mixing and in turn the rate of heat release for a given combustor geometry. The presented work attempts to investigate the effect of inclined injection configurations on the performance of a scramjet for a typical combustor geometry having intrusive fuel injection using strut. Over a decades of literature points towards the fact that numerical simulations are widely being accepted as promising method of investigation of flow inside a scramjet. Reacting simulations of hydrogen injection in an inlet air stream of Mach 2.5 are done with various fuel injection configurations. After validation of simulation results with the available experimental Sadatake Tomioka et al. (2001) results, different injection configurations were simulated for a constant equivalence ratio. The maximum combustion, mixing and heating was observed in near the strut surface, hence flow fields of these configurations are studied near the strut to understand the mechanism of mixing. Observations on performance parameters like total pressure loss, maximum top wall static pressure, flow enthalpy etc. are made to compare these configurations.