Experimental characterization of flow field around a square prism with a small triangular prism

Abstract

The characteristics of the flow field around a square prism containing a small triangular prism upstream were investigated by measuring lift and drag and visualizing the flow field through particle image velocimetry. Experimental parameters included triangular prism-to-square prism width ratio (H/B, H and B are side lengths of the triangular and square prisms, respectively) and triangular prism-to-square prism gap ratio (G/B, G is the gap distance between the triangular and square prisms). The drag reduction rate of the square prism increased and then decreased with increasing G/B at a constant H/B but increased with increasing H/B at a constant G/B. The maximum drag reduction rate was 78.5% at H/B = 0.6 and G/B = 1.5. The width and gap ratios also minimally affected the lift reduction rate of the square prism, with an average value of 52.4%. Stagnation regions were further observed upstream and downstream of the square prism.