Control of subsonic separation bubble in hypersonic intake using perforated wall

Abstract

The SCRAMJET engine uses the external and internal compression with the help of compression shockwaves to obtain the static pressure rise for the supersonic combustion The efficiency of the intake and isolator determines the overall engine performance The intake performance is reduced due to the shockwave boundary layer interaction SWBLI and the backpressure induced by the supersonic combustor In this research, a hypersonic intake with three successive semi wedge ramps was designed based on the shock wave theory for the SCRAMJET engine The hypersonic intake was designed in such a way to meet the Kantrowitz inlet self starting limits for upersonic/hypersonic intakes The performance of the inlet was evaluated based on the numerical simulation In the first part of the research the shock wave boundary layer interaction SWBLI induced separation bubble formation SB and its control has been investigated numerically in the mixed compression intake of the scramjet engine The external compression has occurred due to the three successive oblique shocks formed from the three successive ramps of the forebody The intake is designed in such a way that all three shocks converge and impinge on the leading edge of the cowl lip for the operating Mach number of 5 0 The numerical simulation is carried out by solving steady compressible 2 D RANS equations using transitional SST k and#969; turbulence model to capture the influence of SWBLI in the performance of supersonic intake The formation of SB and its control by establishing the perforated wall in its proximity are investigated for three different cases based on the perforation with respect to SSB Findings of the numerical simulation have concluded that the size of the SB decreases to an acceptable level while establishing the perforation in the entire fore body wall in the isolator region newline