リング設置による円柱の抗力および変動力低減
2005 年 71 巻 704 号 p. 1075-1083
詳細
2005 年 71 巻 704 号 p. 1075-1083
The present experiment demonstrated an omnidirectional reduction of drag and fluctuating forces of a circular cylinder to the cross-flow by attaching cylindrical rings, which were spaced several diameters along span. The Reynolds number based on the diameter of the base cylinder, Red, ranged from 3 000 to 38 000. For Red≥20 000, the drag force was markedly reduced by 15% although the projected area to the flow was increased. This is attributed to the formation of the separation bubbles on both sides of the ring due to the turbulent transition in the boundary layers. The fluctuating lift, which was estimated from the fluctuating surface pressures, was much reduced throughout the examined Reynolds numbers due to the suppression of the vortex shedding.
