Experimental Investigation of Flow Past an Elliptic Cylinder near a Plane wall

The flow characteristics around an elliptic cylinder with an axis ratio of AR=2 located near a flat plate were investigated experimentally. The elliptic cylinder was located on the inside and outside a turbulent boundary layer region whose thickness (8) is 0.38B. The Reynolds numbers based on the height of the cylinder cross-section were 15000 and 30000. The wake velocity profiles and turbulence intensities behind the cylinder were measured using hot-wire anemometry. The ground effect of the cylinder at a small gap ratio constrains the flow lower side of the cylinder wake. This constraint effect is more severe for the Re=15000, compared to the Re=30000. The wake region behind the elliptic cylinder is relatively small and the velocity profiles tend to approach rapidly to those of a flat plate boundary layer.