Power-Law Shaped Leading Edges in Rarefied Hypersonic Flow

摘要

A numerical study is reported on power-law shaped leading edges situated in a rarefied hypersonic flow. The work is motivated by interest in investigating the flowfield properties of power-law shaped leading edges as possible candidates for blunting the geometry of hypersonic leading edges. The sensitivity of both the flowfield structure and 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 coefficient for the flow conditions considered is in surprising agreement with that obtained by simple Newtonian theory, which predicts that a class of power-law shapes 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 finite 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 finite value exactly at the nose.