地面に近接して回転する円筒まわりの流れ : 第2報

抄録

We have presented the effects of a ground plate (stationary or moving) on the Magnus effect of a rotating cylinder in the first report and showed that the lift suddenly changed at a certain H/D, and the phenomenon was related to a change in the flow pattern. Details of the phenomenon that is unstable and hysteretic are studied experimentally. To determine the critical points of the hysteretic phenomenon appearing with the changing in flow patterns with α, the velocity vector is measured by a hot-wire anemometer for the clearance H/D and velocity ratio α. As a result, it is found that two different flow patterns exist in a certain area enclosed by H/D and α. We call this area a "bistable area". The influence of Reynolds number on the bistable area is also discussed.