초록 열기/닫기 버튼
Plasma wind tunnel is one of the devices that simulates hypersonic, high enthalpy environments on the ground. The diffuser, which is one of the components of the plasma wind tunnel, captures the flow ejected from the nozzle and compresses the flow, thereby enabling stable and economical test. In this study, numerical analysis was performed on the flow inside the diffuser to understand the nature of the flow and pressure recovery performance with different diffuser shape. Inflow conditions were Mach 7, 2 kg/s of mass flow rate, 530 Pa of static pressure, and 240 K of static temperature, which is based on the conditions of MW-class large capacity plasma wind tunnel. In the flow inside of a diffuser, strong shock resulted in severe total pressure loss and the pressure ratio required to operate wind tunnel. In order to investigate the influence of the change in diffuser shape, pressure recovery performances of each diffuser were compared varying diffuser converging section, throat area, and diverging section. In diffuser converging section, the pressure recovery performance was improved as the intensity of the oblique shock decreased. For the diffuser throat, the smaller the throat area, the more improved the pressure recovery. The change of the diffuser pressure recovery performance with the shape change of diverging section was relatively small. These comparative analysis could be useful for design of a diffuser for plasma wind tunnel.
