《05 Interaction of A Cavitation Bubble and An Air Bubble with a Rigid Boundary 》.pdf

503 2010,22(4):503-512 DOI: 10.1016/S1001-6058(09)60082-2 INTERACTION OF A CAVITATION BUBBLE AND AN AIR BUBBLE * WITH A RIGID BOUNDARY XU Wei-lin State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China, E-mail: xuwl@scu.edu.cn BAI Li-xin Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China ZHANG Fa-xing State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China (Received March 23, 2010, Revised June 30 2010) Abstract: The motion of a spark-induced cavitation bubble and an air bubble near a rigid boundary is experimentally studied by using high-speed photography. Several dimensionless parameters are used to describe the geometrical configuration of the bubble-bubble-boundary interaction. The bubble-bubble interaction can be considered in two different conditions. The cavitation bubble will collapse towards the air bubble if the air bubble is relatively small, and away from the air bubble if the air bubble is relatively large. The two zones are identified in the bubble-boundary interaction, and they are the danger zone and the safety zone. The relative position, the bubble-boundary distance and the bubble-bubble distance play important roles in the bubble-bubble-boundary interaction, which can be considered in several conditions according to the responses of the bubbles. Air jets are found to penetrate into the cavitation bubbles. The cavitation bubble and the air bubble (air jet) move in their own way without mixing. The motion of a cavitation