高超声速风洞扩压器试验研究与分析

扩压器是高超声速风洞的关键部件，主要作用是提高出口气流的静压。在某高超声速风洞扩压器上布点测量壁面静压和近壁面皮托压力，并在出口布置尖劈测量出口气流参数，评估扩压器的性能。结果表明：扩压器内的核心流区由于存在逐步衰减的激波-膨胀波系，使气流出现“减速-加速-再减速-再加速”的流动过程；该扩压器能保证风洞正常启动以及试验段流场不受背压的影响；该扩压器的效率与国外类似风洞扩压器效率相当，前室总压较低时，扩压器能起到良好的减速增压的效果，前室总压较高时，扩压器增压效果不明显，扩压器出口气流马赫数偏高。

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.