Power law shaped leading edges in rarefied hypersonic flow

Abstract

A numerical study is reported on power-law shaped leading edges situated in a raree ed hypersonic e ow. The work is motivatedby interest in investigating thee owe eld propertiesofpower-lawshapedleading edgesaspossible candidatesforbluntingthegeometryofhypersonicleading edges.Thesensitivityofboth thee owe eld structureand surface quantities to shape variations of such leading edges is calculated by using a direct simulation Monte Carlo method. Particular attention is focused on the pressure gradient along the body surface and on the heat transfer to the body. Calculations showed that the pressure coefe cient for the e ow conditions considered is in surprising agreement with thatobtained by simpleNewtonian theory,which predictsthat a class of power-lawshapes exhibits aerodynamic behavior different from that expected for classical blunt shape. Simulations also showed that the stagnation point heating on power-law leading edges with a e nite radius of curvature follows the same relation as that for classical blunt body. However, for those leading edges with zero radii of curvature, the heat transfer behavior follows another pattern in the vicinity of the stagnation point, reaching a e nite value exactly at the nose.