Open Channel Flow Over Pairs of Rectangular and Streamlined Cylinders at Incidence

This paper reports an experimental investigation of the mean flow and turbulence characteristics around pairs of identical rectangular and streamlined cylinders in an open channel. The cylinder pairs were inclined at different angles of incidence angles relative to the streamwise direction of the approach flow. The rectangular cylinders and the 12% symmetric airfoils cylinders are made of transparent acrylic plates of length, L = 100 mm and maximum thickness, D = 12 mm. The centre-to-centre spacing between the cylinders was 51 mm. The blockage ratio produced by the cylinder pairs was 0.13 at zero angle of incidence. For each cylinder pair inclination, a high resolution particle image velocimetry technique was used to conduct detailed velocity measurements in the streamwise-spanwise plane. From these measurements, iso-contours and profiles of the mean velocities and turbulence statistics were obtained to study the effects of cylinder geometry and inclination on the flow around the cylinder pairs.