正方形柱に働く抗力の軽減に関する研究 : 第1報, 小さな渦発生体による流れの制御
1993 年 59 巻 568 号 p. 3701-3707
詳細
1993 年 59 巻 568 号 p. 3701-3707
Experimental studies on drag reduction of a square prism were conducted. To control the flow around a square prism, a small vortex shedder was set up upstream of the prism. The side of the prism, D, was 30 mm and the Reynolds number was Re=3.2×104. The diameter of the rod used as the vortex shedder, d, ranged from 1 to 6 mm, and the space between the prism and the rod, G, was varied. The results obtained are as follows. The critical space GC, is given as GC=D+4.5d, where vortex shedding from the rod disappears. The Strouhal number of the prism decreases at G>GC and increases at G≤GC. In the range of 0.1≤d/D≤0.2, drag of the prism decreases about 50% at G>GC and 70% at G≤GC.
