二元内流通道内湍流附面层分离的数值与实验研究

本文应用激光多普勒测速仪测量了二维扩压器中不可压湍流附面层分离流动,得到了时均速度和表面压强分布,表面摩擦系数和时均速度分布经验关系式做了比较。预测中采用准同时粘性/无粘流匹配模型,并比较了两种形状因子H_1经验关系式所得预测结果。在最大反流以前,所预测的附面层位移厚度及形状因子与实验吻合。

Numerical and Experimental Study on Turbulent Boundary-Layer Separation in a 2-D Internal Channel

An incompressible turbulent boundary layer separation in a two-dimensional diffuser was surveyed by using laser Doppler velocimeter. Mean and turbulence quantities were obtained. The skin friction coefficient and mean velocity profiles were compared with several experience relationships. The experiment shows that the boundary-layer shape factor H is somewhat small in Intermittent Transitory Detachment (ITD) and Transitory detachment. Bardina's velocity profile deduced from Coles wake law is in agreement with the present experiment before ITD and after ITR. Cross' profile could fit the experimental results well in the recirculating flow. Prediction was made by using a quasi-simultaneous vis-cous/inviscid interaction model and was compared with the experiment. Two experience relationships of shape factor H1 = H1(H) were applied in the prediction. The prediction of the boundary-layer parameters is in agreement with the experiment before the strong reversing flow by using Williams' shape factor relationship.