抄録
The behaviour of spiral vortices and the detailed process of boundary layer transition were observed for circular disk, cones and spheres rotating in still air or in axial air flow. Flow patterns in the transition region were visualized by spreading titanium tetrachloride on the rotating test bodies, while a hot-wire anemometer was used to measure the velocity field. The results show that the spiral vortices are relatively fixed to the rotating body surface, and that there are two types of the cross-sectional flow pattern for the spiral vortices, which correspond to two types.of the transition process. The critical and transition Reynolds numbers, the direction of the vortex axis and the number of the vortices on the rotating bodies were also measured.
