Numerical simulation of flow around a circular cylinder with curved sectional grooves
In a circular cylinder with uniform flow, a sudden decrease in the drag force occurs at a high Reynolds numbers; however, it is known that the same phenomenon occurs at a lower Reynolds number in the case where there exist grooves or roughness on the circular cylinder surface. To clarify the flow characteristics around a circular cylinder in the case of changing the shape of grooves we analyzed the drag coefficient, lift coefficient, turbulent kinetic energy, vorticity and pressure by applying the RNG k-epsilon turbulent model. The shapes of the grooves were arced, triangulated and curved. The results showed that the separation point for a circular cylinder with curved sectional grooves shifts to the most downstream side and the drag coefficient becomes the smallest among circular cylinders with grooves.
curved sectional grooves flow characteristics drag coefficient circular cylinder with grooves numerical visualization