Investigation of the Conical Flowfield Around External Axial Corners.

Abstract

An experimental investigation has been made of the supersonic flowfield around symmetric and asymmetric external axial corners formed by the juncture of two wedges. The measurements were performed at a Mach number of 2.95 in a 15-cmxl5-cm blow-down wind tunnel at a Reynolds number of 4 x 10/cm. A five-hole conical-head probe that measures pitot pressure and flow angularity was used to explore the flowfield; also, surface oil-flow pictures were taken. The main purpose of the experiments was to provide an answer to questions about the nature of the conical stagnation points. In the symmetric case three conical stagnation points were detected: a saddle point at the corner, flanked by a node on each wedge surface. In the asymmetric configuration, the flow was found to spill over the corner toward the lower pressure side, forming a separated region. Depending on the degree of asymmetry, the separated region contained one or more vortices. It is suggested that a nodal conical stagnation point occurs on the lower pressure surface beyond the separated region.