Flow structures around a three-dimensional rectangular body with ground effect

Abstract

An experimental investigation of the flow over the rectangular body located in close proximity to a ground board was reported using the particle image velocimetry (PIV) technique. The present experiments were conducted in a closed-loop open surface water channel with the Reynolds number, <TEX>$Re_H=1.2{\times}10^4$</TEX> based on the model height. In addition to the PIV measurements, flow visualization studies were also carried out. The PIV technique provided instantaneous and time-averaged velocity vectors map, vorticity contours, streamline topology and turbulent quantities at various locations in the near wake. In the vertical symmetry plane, the upperbody flow is separated from the sharp top leading edge of the model and formed a large reverse flow region on the upper surface of the model. The flow structure downstream of the model has asymmetric double vortices. In the horizontal symmetry plane, identical separated flow regions occur on both vertical side walls and a pair of primary recirculatory bubbles dominates the wake region.