Viscous Performance Map of a Blunt Streamline-Traced Busemann Inlet

Abstract

A computational study of the viscous performance of a blunt leading-edged, streamlinetraced Busemann inlet with no truncation was performed. A sugar scoop style of Busemann inlet with geometric contraction ratio 7 and leading edge radius of 0.03” was sized for a nominal inviscid mass capture of 10 lbm/s at Mach 7, 0° angle of attack, and a dynamic pressure of 1000 psf. Solutions were obtained at angles of attack ranging from -5° to 10°, in increments of 5°. All angles of attack were calculated at Mach numbers ranging from 5 to 8, in increments of 1. Additional lower Mach number solutions were obtained for each angle of attack to determine operability limits for minimum running Mach number. Conservationaveraged performance results for total pressure ratio and Mach number were compiled at both the cowl lip and inlet throat planes and compared with area- and mass-averaged results. Lift, drag, and pitching moment coefficients were integrated to both the cowl lip and inlet throat planes. Performance trends were presented, showing that the inlet performance correlated well with a drag coefficient referenced to the freestream streamtube area captured by the inlet. Comparisons between the data and existing correlations for maximum contraction ratio showed good agreement when using inlet cowl plane Mach number and internal contraction ratio.