Flowfield characteristics of struts in supersonic annular flow

Abstract

Abstract This paper describes a combined experimental and numerical study of supersonic flow over four, circumferentially equidistant, diamond-shaped struts positioned within an annular flow passage formed by a cylindrical cowl and centerbody. The experimental results include static pressure, pitot pressure, total pressure, and Mach number distributions at two streamwise locations downstream of the strut trailing edge. Resultant cross flow vectors based on yaw and pitch angle measurements in the flow are also presented at these two locations. The experimental results are compared with numerical predictions based on a combined version of the Baldwin–Lomax and P.D. Thomas turbulence models. Experimental and numerical results are in good agreement throughout wall-bounded regions of the flow, including regions that contain propagating shock and expansion waves. The predictions do not simulate, however, the presence of vortices in the wake region downstream of the strut trailing edge and their distorting influence on flow in this region. This discrepancy is attributed to the prescribed zero-equation (isotropic eddy viscosity) turbulence model, which apparently cannot simulate the effects of streamwise vorticity in a supersonic wake.