Abstract
This paper describes the drag reduction of square cylinders with the corner-cuttings and with grooves, such as riblet, on the surface of the square cylinders. We carried out wind tunnel tests for the measurements of the drag coefficient, the surface pressure acting on a square section cylinder with chamfered corner and grooves. In addition, the flow visualization by Spark tracing method has been carried out. It is found that the drag coefficients of the square cylinder with chamfered corner and with grooves reduce in comparison with the square cylinder without chamfered corner and without grooves. As the depth of grooves increased, drag coefficient become lower.
