Experimental Measurement of Vortex Cavitation around a Suction Pipe Inlet

Abstract

Cavitation due to a suction vortex (vortex cavitation) is an important problem in some fluid machinery fields, such as fast reactors. In this study, a water experiment on vortex cavitation is carried out using a simple cylindrical vessel with a suction nozzle. In order to understand the fundamental behavior of vortex cavitation, its instantaneous occurrence behavior is grasped by visualization using high speed camera. Velocity distribution around vortex, which causes cavitation, is also quantitatively grasped by means of Particle Image Velocimetry. From visualization measurements, vortex cavitation is considered to be triggered by a wall nuclei and the cavity develops immediately toward the suction nozzle once triggering occurs on the bottom wall. In addition, distribution of pressure decrease along vortex center estimated based on Burgers model and measured velocity distribution shows monotone increase from the bottom wall toward the suction nozzle. As the results, the cavity is thought to develop toward the suction nozzle intake immediately, if some triggering of cavitation occur on the bottom wall.