C243 回転球まわりに生成する渦流の崩壊過程の可視化

抄録

The spiral vortex flows around a rotating sphere with smooth surface in still air were visualized by means of smoke-injection and smoke-wire method. The experiment was conducted at the rotating speed of the sphere with a diameter of 100mm at the range of 2280rpm. It was found that the air-jet flows spread from the equator of the sphere and the spiral vortex accompany with it. As the increasing rotating speed, the breakdown position of the vortex flows approached the sphere surface. Furthermore, the distributions of the tangential and radial components of the flow velocity and turbulent intensity around the rotating sphere were measured using a hot-wire anemometer with an x-probe. The measured results were compared with the visualized smoke patterns, and were also discussed the breakdown process of the vortex flows.