Computational study of the flowfields associated with oblique shock/vortex interactions

Abstract

The interaction between a supersonic streamwise vortex and an oblique shock is solved numerically using the unsteady, three-dimensional Euler equations. The parametric study ascertains the effects of vortex strength, streamwise velocity deficit, and Mach number on the oblique shock/vortex interaction. The vortex, whose tangential and streamwise velocities are analytically modeled, is introduced upstream of the shock and allowed to interact with the shock. The interaction is examined at freestream Mach numbers of 3 and 5, using vortices of varying strength and possessing various velocity deficits. Three distinct types of interactions—weak, moderate, and strong—are observed, depending very strongly on the streamwise velocity deficit and, to a lesser degree, on the strength of the vortex. The weak interaction is characterized by a slight distortion of the shock and vortex with the resulting flowfield being supersonic everywhere. The moderate interaction, however, results in a more pronounced distortion of the shock, creating a small pocket of subsonic flow downstream of the interaction. In addition, the incident vortex is highly distorted by the shock and eventually splits up into two counter-rotating vortices. In the strong interaction, due to the formation of a large subsonic region, a dramatic reorganization of the original shock occurs, accompanied by a region of reversed subsonic flow, a stagnation point, and a drastic expansion of the vortex core, all of which are characteristics of vortex breakdown.