Journal article

Experimental investigation of boundary layer transition in flow past a bluff body

Rahul Deshpande, Aditya Desai, Vivek Kanti, Sanjay Mittal, CP Tso (ed.)

FIFTEENTH ASIAN CONGRESS OF FLUID MECHANICS (15ACFM) | IOP PUBLISHING LTD | Published : 2017

Abstract

We explore the phenomenon of drag crisis observed for the flow over bluff bodies at high Reynolds numbers. The drag coefficient reduces significantly beyond a certain Re due to the transition of the boundary layer from laminar to turbulent state. Flow past a smooth sphere and a circular cylinder is experimentally investigated for 1.0 × 105 ≤ Re ≤ 5.0 × 105 via unsteady force, surface-pressure and 2-D Particle Image Velocimetry(PIV) measurements. In case of a smooth sphere, the drag crisis is observed for Re > 3.3 × 105. The unsteady force measurements reveal that the fluctuations in the force coefficients initially increase with Re in the high subcritical regime and then experience a steep f..

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University of Melbourne Researchers