Affiliations: Department of Mechanical Engineering, Kanagawa
Institute of Technology, 1030 Shimoogino, Atugi-shi, Kanagawa 243-0292, Japan.
E-mail: [email protected] | School of High-Technology for Human Welfare, Tokai
University, 317 Nishino, Numazu-shi, Shizuoka 410-0395, Japan
Abstract: 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 – ε
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.
