Inlet-Entry Boundary-Layer Impact on Isolator Aerothermal Performance with Microvortex Generator Control

This study numerically analyzes the Mach 5 flowfield within an integrated inlet/isolator configuration equipped with a microvortex generator (MVG). The impacts of inlet turbulent boundary-layer thickness on shock topology, isolator performance, and surface aerothermal loading are evaluated under both undisturbed throughflow and stabilized backpressure conditions. Deviation from theoretical oblique shock angles demonstrates that boundary-layer thickening amplifies shock curvature, driven by the intensified adverse pressure gradient within the turbulent boundary layer. Increased shock curvature drives the shock system upstream during undisturbed throughflow while promoting the rapid movement of separation shock waves under stabilized backpressure conditions. Vorticity analysis reveals that a thickened boundary layer diminishes the capacity of MVG-generated vortices to entrain freestream momentum into the near-wall region, resulting in an improvement in the total pressure recovery coefficient. Furthermore, wall heat flux decreases as the boundary layer thickens. Specifically, in undisturbed throughflow, peak heat flux coefficients on the upper and lower walls decrease by 12.2% and 24.2%, respectively. Under stabilized backpressure, shock-induced aerothermal intensification exhibits a dual-mode behavior, resulting in either amplified or attenuated heat flux escalation. Amplification factors ranging from 2.5 to 4.5 are observed at monitoring points, with severe aerothermal zones exhibiting progressive lateral expansion corresponding to boundary-layer thickening.