SHOCK-WAVE SHAPES AND SURFACE PRESSURES ON HEMISPHERE- AND CONE-CYLINDERS IN LOW-DENSITY HYPERSONIC FLOW INCLUDING ABLATION

摘要

Shock-wave shapes and surface pressures were determined in air for highly cooled hemisphere- and cone-cylinders with and without ablating noses. The test Mach number was 14. The test Reynolds numbers of 9000 and 1000, based on the cylinder diameter, were estimated to be in the boundary-layer and merged-layer flow regimes, respectively- Comparisons with the predictions of viscous-interaction theory have been made and the range of validity for the theory has been assessed.nThe results show that in the merged-layer regime viscous-interaction theory can predict the shock-wave shapes for these bodies but fails to predict the surface pressures on the bodies. With merging, the surface pressures on the hemisphere-cylinder decreased below the predicted inviscid pressures. The behavior of the shock waves and surface pressures for these bodies in the merged-layer regime is qualitatively the same as that previously observed for sharp bodies.nNose ablation displaced the shock waves outward and increased the surface pressures on the bodies for a short distance behind the noses. These trends were qualitatively predicted by viscous-interaction theory.