Physical and computational aspects of shock waves over power-law leading edges

Abstract

Computations using the direct simulation Monte Carlo ͑DSMC͒ method are presented for hypersonic flow on power-law shaped leading edges. The primary aim of this paper is to examine the geometry effect of such leading edges on the shock-wave structure. The sensitivity of the shock-wave shape, shock-wave thickness, and shock-wave standoff distance to shape variations of such leading edges is investigated by using a model that classifies the molecules in three distinct classes: ͑1͒ undisturbed freestream, ͑2͒ reflected from the boundary, and ͑3͒ scattered, i.e., molecules that had been indirectly affected by the presence of the leading edge. The analysis showed that, for power-law shaped leading edge with exponent between 2 / 3 and 1, the shock wave follows the body shape. It was found that, at the vicinity of the nose, the shock-wave power-law exponent is 1 / 2. Far from the nose, calculations showed that the shock-wave shape is in surprising qualitative agreement with that predicted by the hypersonic small disturbance theory for the flow conditions considered.