Flow Characteristics of a Square Cylinder with Different Angles of Attack Submerged in Oscillatory Flow.

Abstract

Experimental investigations on the flow characteristics of the forces acting on and the flow patterns around square cylinders at different angles of attack (0°≤α≤45°) submerged in oscillatory water flow were carried out. Both in-line and transverse forces were simultaneously measured in a relatively wide range of Keulegan-Carpenter number (KC) from 1 to 90. The force signals were spectrally analyzed to get dominant frequencies, and flow visualization technique was also employed to understand the correspondence between flow patterns and force coefficients. We have discussed the influence of the angle of attack of the cylinder on the flow pattern and fluid dynamic characteristics of a square cylinder. Further, force coefficients and Strouhal numbers compared with the results obtained in steady flow.