Instability and transition in supersonic boundary layers

Recently obtained flight transition data for a 5-deg half-angle cone at Mach numbers of 1.2, 1.35, 1.6, and 1.92, together with 'quiet' tunnel data at Mach 3.5, are analyzed by linear compressible stability theory. The results obtained indicate that the exponent N ranges in value between 9 and 11, which is in keeping with values previously determined for subsonic flows. Computations show that the transition in both the flight and quiet wind tunnel experiments was due to oblique first-mode disturbances.