A Study on the Supersonic Internal Flows with Pseudo-Shock Waves

Abstract

This paper describes an experimental study on the supersonic internal flows with Pseudo-Shock Waves (PSW) in a straight square duct with cross section of 80×80mm^2, using the pressure-vacuum type Mach 4 supersonic wind tunnel of Muroran Institute of Technology. The free stream Mach number and unit Reynolds number just upstream of the PSW were M_∞ = 3.98, Re_∞ = 2.6×10^7. Flow structure of the Mach 4 PSW was clarified by color schlieren photographs and the wall surface shear stress was visualized qualitatively by Shear-Sensitive Liquid Crystal. It. reveals that the turbulent boundary layer on the top or bottom wall of the duct separates in large just after the first shock wave of the PSW, and the internal flow of the PSW becomes asymmetric flow.