绕凸台的高超声速分离流动研究

Separated Flow over the Protuberances in Hypersonic Flow

本文研究高超声速流动绕三维低凸台的流动特性。凸台高度与边界层厚度之比介于0.5～0.8,凸台周边倾角介于14°～45°。在高超声速风洞中,来流马赫数为5,单位雷诺数为2.6～6.0×10~7/米。实验过程中测量了模型中心线及特殊部位之表面压强分布,根据纹影记录及表面流动显示确定激波与边界层干扰流场特性及分离区的变化。发现分离区在中心线上距凸台最远,而在凸台肩部距周边沿法线方向最近,确定了中心线上最大压强比的位置。

The hypersonic flow over 3D low protuberances are studied in this paper.The ratio of height of protuberance to boundary layer thickness is from 0.5 to 0.8, and the oblique angles at round edge can be changed.The tests are performed in a hypersonic wind tunnel, free stream Mach number is 5, and Reynolds number is 2.6-6.0×107 per meter.The pressure distributions along the centre line of models and special positions are measured, the visualizations including schlieren graph in space and oil flow patterns on the wall are taken. It shows the flow field of shock wave/boundary layer interaction and separated flow regions. The positions of maximum and minimum distances between separation line and models are found, the maximum pressure ratio at the centre line is determined.