考虑进气道喉道非均匀流场影响的隔离段直连试验

Direction Connect Test on Isolator Considering Effects of Nonuniform Flow at Inlet Throat

为了研究进气道喉道非均匀流场对隔离段流动特性的影响，设计了能模拟隔离段入射激波和非对称附面层的直连试验装置，并进行了马赫数3.0，3.4和3.8的吹风试验，完成了壁面静压、纹影和NPLS测量，获得了有效的试验数据。结果显示，唇口角对隔离段直连台的起动和耐反压能力影响非常大，随着唇口角度的增加，隔离段的极限反压降低，降低幅度达到22%-32%。与均匀来流相比，激波串很难稳在隔离段入口附近，造成激波串极易被推出隔离段。激波串形态受隔离段入射激波和肩部附近附面层状态的影响较大。NPLS测量系统观察到隔离段内部流场精细结构，如下壁面附面层的转捩现象、激波串的马赫盘、分离和滑移线等。

In order to investigate the effects of nonuniform flow at inlet throat on the flow characteristics of isolators,a direct connected experimental facility was designed to simulate the lip shock wave and asymmetric boundary layer at the isolator entrance. The experiment with nonuniform flows at the isolator entrance was con？ducted in a wind tunnel at Mach 3.0,3.4 and 3.8,respectively. Pressure distribution at wall,schlieren photograph and Nano-tracer Planar Laser Scattering（NPLS）were measured in the experiments. The results indicate that lip angle has significant effects on the starting and anti-pressure capability of isolator. With the increase of lip angle , the maximum back pressure of the isolator decreases and the range is between 22%and 32%. Shock train in the isolator with a nonuniform entrance flow is relatively more unstable and easily being pushed out of the isolator compared with that of a uniform entrance flow. The lip shock wave and asymmetric boundary layer have great in？fluence on the shape of shock train. Results show that flow structures such as transition phenomenon on the lower wall,mach disk,separation flow and slip lines could be revealed distinctly by NPLS.