A computational study was conducted to determine the effects of the degree of thermal and chemical nonequilibrium on shock layer profiles. The shape of these profiles affects the propagation and amplification of boundary layer disturbances which lead to boundary layer transition. The Navier-Stokes equations were employed to compute the mean laminar flow of air over a sphere-cone vehicle at hypersonic flight conditions. Mean flow profiles, distributions of angular momentum, and boundary layer thicknesses, which are indicative of first and second mode inviscid instability characteristics, were obtained with finite rates versus equilibrium-like or frozen-like flow. Increasing the freestream velocity and decreasing the altitude had a larger effect on the profiles than varying the nose radius and wall temperature. The results suggests that a finite rate nonequilibrium model is essential for accurately examining boundary layer stability.
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