Control of subsonic separation bubble due to shock wave-boundary layer interaction using porous wall

The investigation of Shock Wave Boundary Layer Interaction (SWBLI)-induced Separation Bubble (SB) formation and control was conducted numerically in a mixed compression intake of a scramjet engine. External compression was achieved through three successive oblique shocks formed by the forebody ramps. The intake was designed so that all three shocks converge and impinge on the leading edge of the cowl lip at an operating Mach number of 5.0. Numerical simulations were performed by solving steady, compressible 2D RANS equations using the transitional SST k–[Formula: see text] turbulence model to analyze the influence of SWBLI on supersonic intake performance. This study examined SB formation and its control by implementing a porous wall near the SB in three configurations based on the perforation relative position to the SB. The results showed that the size of the SB decreased to an acceptable level when the upstream section of the bubble was solid, and the downstream section was porous. The porous wall downstream of the separation bubble effectively reduced the bubble’s size and mitigated its negative impacts on intake performance. This study demonstrates that strategically placing porous walls can optimize the aerodynamic efficiency of scramjet engines operating at high Mach numbers. The findings provide valuable insights for designing future hypersonic vehicles, where managing SWBLI is critical for ensuring structural integrity and operational efficiency under extreme conditions.