Characteristics and Mechanisms of the Zigzag and Spiral Movement of Rising Bubbles in Still Water

When a bubble rises freely in still water, it often moves along zigzag or spiral trajectory. In order to explore the mechanism of this movement, an experiment was conducted record changes movement trajectory and shape. The results show that can be explained by swing trailing vortices change vorticity. There is asymmetric shedding vortices. velocity caused will lead vorticity Two factors drag force on both sides bubble, resulting Only when aspect ratio λ reaches 2.0 move zigzag. moving two orthogonal directions not only but also its effect equivalent low-pressure area around bubble. trajectory, at swings back forth plane, flatter. rotates becomes more spherical. Compared with has higher lower frequency