Study of Stability of Hypersonic Boundary Layer over a Circular Cone at Small Angle of Attack with DNS Method

Abstract

An investigation on the stability of hypersonic boundary layer over a 5o half-angle cone with 1mm nose radii at 0.5o angle of attack (AoA) is performed by direct numerical simulation (DNS) at free stream Mach number 6.0 and at unit Reynolds number 1.0E+7/m. After obtaining the undisturbed steady flow, three-dimensional Navier-Stokes equations in perturbation form are solved X=300.0~401.4Rn with a third- order temporal and spatial accuracy finite difference method. Two-dimensional multiple disturbances are introduced at the inflow section of hypersonic boundary layer and then their spatial evolution are simulated. The present results show that three- dimensional waves in the circumferential direction are generated with the development of the two-dimensional disturbances, and a kind of interferential streak structure is formed along the streamwise direction. The perturbation parameters reveal that their magnitude on the leeward region is much larger than that on the windward region.