凹曲面に沿う縦渦の生成と崩壊

抄録

The generation and breakdown of longitudinal vortices in the boundary layer along a concave wall has been studied experimentally. The experiments have been carried out using the concave wall 1m in radius of curvature at air velocity range 2 to 5m/s. The air flow has been made visible by evaporated-gas-oil smoke, and the flow patterns have been stereographically photographed from upper, lateral and rear sides with Strobo. It is noticeable that the vortices are formed into pairs of ones downstream, and that arch shaped vortices which lie across each of these pairs generate periodically and gradually break down. Such phenomena are compared with velocity distributions and frequency of the arch shaped vortices. The mechanism of these vortices is also investigated.