变高度圆柱诱导的激波边界层干扰

SHOCK WAVE AND TURBULENT BOUNDARY LAYER INTERACTIONS INDUCED BY CIRCULAR CYLINDERS WITH VARIOUS HEIGHTS

采用分区方法及Roe三阶流通量差分分裂格式求解雷诺平均N－S方程，湍流附加黏性系数用Baldwin－Lomax模型计算，数值模拟了高超声速条件下变高度圆柱诱导的激波边界层干扰，其流场的主要特性均与实验结果一致或规律相同，结果清晰地展示了流场结构以及气动载荷分布随柱高度的变化特征，并说明激波碰撞和旋涡运动都可能导致飞行器表面局部气动载荷的增加．

Hypersonic flows around circular cylinders with different heights mounted on a plate are typical kinds of aerodynamic problems. Experimental investigation has evidenced that the interaction flowfields have a gradual change state with the cylinder's height under the condition of equivalent length between cylinder diameter and boundary layer thickness. From the measured pressure distributions three kinds of interaction flowfields can be obtained and the ranges of geometric parameter for each kind is determind.In present paper numerical simulations are made for the shock/boundary layer interaction flowfields by composite grid scheme and Reynolds-averaged Navier-Stokes equations. Turbulent eddy viscosity coefficient is computed by modified Baldwin-Lomax turbulence model. Roe thirdorder flux difference splitting algorithm is employed for the computation. This algorithm is proper to the description of shock and boundary layer and higher order scheme can improve resolution for the separated flow and reduce the number of gridpoints. The numerical results include not only the pressure and heat transfer distributions on the typical body surface lines but also some detailed flowfields structures captured difficultly in experiment such as recompressive suspension shock near the rear edge of cylinder's tip, separation flow patterns on cylinder and on the plate downstream.By comparison with experimental data and analysis the conclusions can be drawn as follows:The main characters of computed flowfields are the same as experimental results. The computational results display clearly the regular patterns of flow structure and distributions of aerodynamic loads under the different heights of cylinders. The shock impingement or vortex motion may result in an increase of aerodynamic load on vehicle.