小円柱による円柱まわりの流れの制御に関する研究 : 第2報,円柱に働く流体力

抄録

In the first report, it was made clear that a small cylinder controlled the shear layer separated from that main cylinder ant that two flow patterns occurred. One the pattern is a forced reattachment and the other is an elongation of the shear layer. This report is concerned with the characteristics of the wake flow of the patterns, namely, the Strouhal number, the time-averaged velocity near the rear stagnation point and the base pressure coefficient which are closely correlated. The rms value of the fluctuating pressure around the main cylinder and the pressure distribution around the small cylinder were measured. Thus, the decrease of the total drag force of the main cylinder including the small one was clarified. It was found that the direction of the fluid force acting on the main cylinder is related to the deflection of the from stagnation point on the main cylinder.