Effects of bleed type on the performance of a supersonic intake

•The porous bleed always improves the total pressure recovery of a supersonic intake.•The slot bleed could decrease the total pressure recovery of a supersonic intake.•The sucked mass flow rate of the porous bleed is smaller than the slot bleed.•The porous bleed is proposed according to the performance point of view for a supersonic intake. An extensive experimental investigation was conducted to reveal the effects of the porous and slot bleeds on the performance and flow control in a supersonic intake. The experiments were conducted on a supersonic intake at the design freestream Mach number of 2.0 and extended to the off-design Mach numbers of 1.8 and 2.2, all at the angle of attack of zero degrees. For every freestream Mach number, eight back pressures were examined, where a total of twenty-four cases were studied. It was found that the slot bleed may degrade the total pressure recovery of the intake, while employing the porous bleed leads to the enhancement of the total pressure recovery. Moreover, the bleed mass flow rate is smaller for the porous bleed and it leads to the lower flow distortion as compared with the slot bleed. However, the slot bleed is more powerful in postponing the buzz onset.