INVESTIGATION OF BOUNDARY-LAYER TRANSITION ON SWEPT WINGS AT MACH NUMBERS 2.5 TO 5

Abstract : Tests were conducted in the 12-in. Supersonic Tunnel of the von Karman Gas Dynamics Facility to determine boundary-layer transition locations on swept wings having a circular arc profile and modified arc profile. Test Mach numbers were from 2.5 to 5 over a Reynolds-number-per-inch range from 0.14 to 1. 08 million at sweep angles of 24, 36, and 50 deg for angles of attack of 0 and approximately -4 deg. Boundary-layer transition Reynolds numbers determined by a pitot probe, and results obtained visually with a sub limable solid are presented. The major factors influencing boundary-layer transition were wing sweep and model leading edge geometry. Increasing wing sweep and leading edge bluntness above a sweep angle of approximately 20 deg decreased the transition Reynolds number at all test Mach numbers.