Abstract
A de Laval supersonic nozzle with test section was designed as the micro-supersonic wind tunnel and it was analyzed numerically and experimentally in this study. The height of nozzle throat was 500 m and the depth was 150 m. A plenum chamber was added to the inlet of supersonic nozzle and a reservoir was connected to the outlet of test section to ensure the steady pressure condition during experiment. The micro-supersonic wind tunnel was fabricated with MEMS lithography technique and Pressure-Sensitive Paint technique was applied to acquire the pressure contours inside the micro-supersonic wind tunnel at various pressure conditions. Good agreement has been established between simulation and experiment. A 4 degree divergent angle was added to the test section to resolve the viscous layer growing from the side walls and ensure the steady flow speed during the measurements. With the inlet pressure of 100 kPa and outlet pressure of 20 kPa, a flow speed of Mach 1.6 can be achieved. A circular cylinder model with diameter of 50 m was positioned at the exit of test section and the microscale shock wave pattern was observed. Due to the viscous effect, the shock wave was smeared but local high and low pressure region can still be identified by Pressure-Sensitive Paint measurements.