Investigation and analyse on the diffuser of hypersonic wind tunnel

Diffuser is the critical part of the hypersonic wind tunnel,The mainly role of the diffuser is to increase the static pressure at the diffuser exit.The wall static pressures and near-wall total pressure pressures along the diffuser are measured,and a measurement rake is installed to measure the flow parameters at the exit of diffuser and evaluate the internal flow performance of the diffuser.The results indicate that the phenomenon of“speed slow-up-slow-up”in inflow of the diffuser appears,the existing diffuser can ensure normal start of the wind tunnel and isolate the test section from disturbance of back pressure;the efficiency of the diffuser is correspond to the similar ones of foreign countries.If the stilling chamber pressure is lower,the diffuser has better effect of reducing speed and boosting pressure;conversely,the effect is not well,the Mach number at the exit is higher.