Viscous Correction and Shock Reflection in Stunted Busemann Intakes

Air intakes play a crucial role in hypersonic air-breathing propulsion by compressing incoming airflow to high pressure and temperature for combustion. Axisymmetric Busemann intakes can achieve highly efficient compression for scramjet engines in inviscid flow. In practice, however, viscous effects exert significant influence on the flowfield and performance of scramjet intakes, necessitating effective methods for viscous correction and intake shortening. The present study develops a robust correction methodology by coupling viscous flow simulations with a wall correction method based on local displacement thickness of the boundary layer, whose edge is detected based on the total enthalpy profile. This iterative correction process is applied to hypersonic stunted Busemann intakes and supersonic M-flow ring geometries. Flow features in the initial inviscid fields are successfully reproduced in the presence of viscosity for both applications, except for highly stunted Busemann intakes, where the mode transition to Mach reflection occurs at different shortening lengths.