扰流片分离流动特性的数值研究

Numerical simulation of separation flow around flaps with varied gap size

在非结构网格下 ,采用SIMPLE算法结合两层带状边界层模型求解雷诺平均N S方程 .研究了底部间隙对平板扰流片引起的分离再附流动结构的影响 .结果表明带底部间隙扰流片的流动结构主要由顶部绕流和底部间隙射流影响 .底部间隙的大小决定了射流的强度 ,最终决定了绕流的结构 .随着底部间隙的增大 ,绕流经历了封闭单涡回流区、射流干扰回流区以及平板绕流 3种流动结构 .它们之间的分界点分别是用扰流片宽无量纲间隙g h =0 .2 ,0 .4.底部间隙 0 .2 <g h <0 .4,底板压力分布基本保持不变 ,因此不会影响其应用于飞机部件的静态气动特性 .

The flow around the plate flaps with base vent was studied by numerical simulation. The Reynolds averaged Navier-Stokes equations were solved by SIMPLE method combined with two-layer zonal boundary layer model. The flow structure depends on the interaction of the separated shear layer from the up edge of the flap and the jet from the base vent. The intensity of the jet is caused by the base vent size and affects the flow structure around the flap. There are three kinds of flow patterns occurred with different base vent sizes. They are closed single vortex re-circulation region, jet and re-circulation region and the closed two vortices wake of flat plate region. The separate points of these three regions are g/h = 0.2, 0.4, here g and h are the sizes of base vent and the flap width, respectively. For the small gap size (0.2 < g/h < 0.4), the flaps all have a large suction re-circulation region, which is similar to that of the case without vent. Hence, the base vent will not reduce the static efficiency of the flap on the wing.