Numerical Simulation of Nose Bluntness Effects on Hypersonic Boundary Layer Receptivity to Freestream Disturbances

Abstract

The accurate prediction of laminar-turbulent transition in hypersonic boundary layers is a critical part of the aerodynamic heating analyses on hypersonic vehicles. Since 1950s, extensive wind-tunnel and flight-test experiments on boundary layer transition and a number of stability experiments have been conducted for hypersonic flows over circular cones [1, 2]. Schneider [1, 2] did an extensive review of the existing literature on these experiments for both flight test and wind tunnel experiments. Though many of these experiments did not measure transition mechanisms and were carried out in noisy wind tunnels, the experimental studies have led to better understanding of the effects on transition of many parameters, including nose bluntness, Mach number, freestream noise, surface and stagnation temperatures, freestream unit Reynolds numbers, cone half angles, angles of attack, and surface roughness, etc. Nevertheless, so far, the effects of many of these parameters on transition are still not well understood.