Trajectory analysis of air-entrainment vortex in a suction sump

Abstract

Abstract We attempt to develop the algorithm that identify the trajectory of the air strings from the image data. As a result, we reveal the behaviour of the vortex. Furthermore, we extract the air string with the longest life, and reveal its trajectory with poor regularity. In some cases, the air string tends to turn back and to attract to the pipe. But in some cases, the air string tends to move linearly and to have the trajectory that moves away from the pipe. In addition, the air string sometimes takes the trajectory that wraps around the wake along the pipe.