Wind Tunnel Investigation and Numerical Simulation of the Near Wake Dynamics for Rectangular Obstacles

An experimental investigation was carried out to study the structure of the flow field around three-dimensional rectangular obstacles. The principal objective was to analyze three-dimensional flow past a single rectangular obstacle and two obstacles placed in tandem by combining the application of a PIV experimental technique and an RSM turbulence model. The study of the flow field around an obstacle was performed in a wind tunnel using a particle image velocimetry (PIV) system. The flow of a fluid around a rectangular obstacle with different attack angles was examined. The results showed the dependence of the flow structure developing around the obstacle on the corresponding Reynolds number, and on the spacing between a pair of tandem aligned obstacles. Detailed quantitative information of turbulence parameters in the vicinity of the obstacle was obtained. Extensive wind tunnel experimental results are presented and compared with numerically simulated ones. A three-dimensional numerical model with the turbulent Reynolds Stress Model (RSM) and a nonuniform grid system was used to examine the effects of a single rectangular obstacle and a double tandem obstacle on the development of the incoming flow. For the case of two rectangular tandem obstacles, the flow patterns were characterized in the gap region as a function of the distance between the obstacles. Good agreement was found between the experimental results of flow and the numerical simulation data.