柔壁自适应风洞低超音速实验技术研究

低超音速三维模型实验是在二维柔壁自适应风洞中进行的。将Wedemeyer理论推广到超音速流动,建立了洞壁调整量的计算方法;解决了洞壁预调量效应的计算问题。在此基础上提出洞壁自适应调整方案,它可用于堵塞比较大的模型实验和任意初始壁面。按此洞壁调整方案所作实验结果表明,二维柔壁自适应风洞作超音速三维模型实验时,可有效地抑制压缩、膨胀波经洞壁反射后对气动数据的影响。其消波效果和三维自适应壁风洞的消波效果基本相同,主激波反射的消波效果甚至优于后者。

EXPERIMENTAL TECHNIQUE RESEARCH ON LOW SUPERSONIC TESTING WITH AN ADAPTIVE FLEXIBLE-WALLED WIND TUNNEL

The exploration has been made of using two dimensional (2 D) flexible walled test section for three dimensional (3-D) model testing at low supersonic speed. The wall adjusting strategy has been established through extending Wedemeyer's theory to supersonic testing cases. The problems of larger blockage model testing and wall readaptation have been studied and a method of calculating the effects of preset wall contour has been developed. Experimental investigations have been conducted in NPU 2 D flexible walled test section with a cone cylinder model of 2% blockage at Mach number 1.2. The results show that the 2 D wall adaptation in supersonic testing is able to greatly reduce the wall interferences stemming from reflections of the compression and expansion waves from 3 D model on the wind tunnel walls. The testing data are also analyzed and discussed through comparisons with some other 2 D and 3- D wall adaptation results.