Abstract: Mach 4 Pseudo Shock Wave (PSW) in a two-dimensional square duct is researched through computational fluid dynamics (CFD) numerical simulation and high-speed color schlieren photography visualization techniques. The experiment was done in the pressure-vacuum supersonic wind tunnel of Muroran Institute of Technology of Japan. The numerical simulation is carried out with the third-order accurate QUICK scheme and Spalart-Allmaras turbulence equation. Experiment is used to validate the CFD model. The computational results show agreement with the experimental results. It can be concluded that the numerical flow visualizations obtained from the present CFD model are accurate. Therefore, the flow quantities, which are very difficult to be obtained experimentally, can be analyzed by numerical simulation. Moreover, the reason that Mach 4 oblique shock wave is asymmetric is conjectured.

Key words: numerical simulation, pseudo shock wave, shock wave/turbulent boundary layer interaction, schlieren experiment, asymmetric characteristic