Crossflow aerodynamic characteristics of a noncircular cylinder withand without strakes

The installation of a pair of thin strakes on the windward side of a flat-faced noncircular cylinder in axial flow at subcritical Reynolds numbers produced substantial changes in the flow pattern, vortex shedding, and drag coefficient. A particular strake configuration resulted in drag reduction of the order of 80%. In this paper, the effects of crossflow angle on drag and lift coefficients of this model are investigated with the help of pressure measurements in a low-speed wind tunnel and flow-visualization tests in a water tunnel. It is found that the drag and lift coefficients of the basic model (no strakes) vary significantly with the crossflow angle, assuming multiple maxima and minima. For a model with strakes, the influence of strakes on the flow pattern and the drag and lift coefficients becomes prominent as the crossflow angle increases. © 1992 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.