The effect of internal contraction, initial rate of subsonic diffusion, and cowl and centrebody shape on the pressure recovery of a conical-centrebody intake at supersonic speeds

Abstract

The effect of internal contraction, cowl and subsonic diffuser shape on the pressure recovery of a 0c = 25 deg conical-centrebody intake designed for a Mach number of 2.46 has been studied experimentally at M = 2.48. Substantial gains in pressure recovery have been recorded with increase of initial angle of the cowl undersurface and the internal, contraction ratio. Small gains were also recorded by decreasing the initial rate of subsonic diffusion and correspondingly increasing the rate at lower duct velocities. Calculations have been made of the increased drag at full mass flow due to excessive internal contraction at Mach numbers below the design value. An empirical correlation of pressure recovery at full mass flow with contraction ratio and initial undersurface angle of the cowl yields results which should aid in the prediction of pressure recovery for conical-centrebody intakes.