Measurements and correlations of transition Reynolds numbers on sharp slender cones at high speeds

Abstract

Abstract : An experimental investigation of laminar boundary-layer transition on a sharp, 10-deg total-angle, insulated cone at zero yaw was conducted in 12- and 40-in. supersonic wind tunnels at free-stream Mach numbers from 3 to 6. This research was directed toward defining the relationship between the aerodynamic noise disturbances and boundary-layer transition Reynolds numbers in high-speed wind tunnels and extended previously published planar results to include axisymmetric models. A significant increase in the Reynolds numbers with increasing tunnel size (similar to the planar results) is shown to exist. Sharp cone transition Reynolds numbers from ten facilities (12- to 54-in.) for free- stream Mach numbers from 3 to 14 and a unit Reynolds number per inch range from 100,000 to 1,200,000 were correlated using aerodynamic-noise-transition parameters. A quantitative correlation of the ratio between cone and planar Reynolds numbers values was developed which demonstrates a strong Mach number dependence and also indicates a variation with tunnel size and unit Reynolds number.