Author(s): Jie Li; Tong Qu; Jiayao Bao; Zhuoqi Zhao
Linked Author(s):
Keywords: Cavitation bubble Elastic boundary Morphology Micro-jet Shockwave
Abstract: Cavitation bubble collapse phenomena near elastic boundaries are widely observed in various fields, including ultrasound medicine and hydraulic engineering. In the present study, the high-speed photography technology and pressure measurement systems are utilized to observe the morphology and shockwave characteristics of spark-generated cavitation bubble collapse near elastic boundary. The results indicate that as the bubble-elastic boundary distance increases, the neck position of the ‘mushroom-shaped’ cavitation bubble decrease followed by a slight increase, while the micro-jet directed towards the boundary exhibits an opposite variation trend. Besides, the shockwave pressure impacting the elastic boundary can be significantly affected by the morphology of bubble and bubble-elastic boundary distance. At γ<0.6, the ‘mushroom-shaped’ cavitation bubble collapses in a direction away from the elastic boundary, resulting in a relatively large collapse shockwave pressure; 0.6<γ<1.4, the ‘mushroom cap’ and ‘stem’ of cavitation bubble move away from and towards the elastic boundary, respectively. The collapse pressure of the cavitation bubble is decomposed into water hammer shockwave, micro-jet impact pressure, ‘mushroom cap’ and ‘stem’ of collapse shockwave; For 1.4<γ, the peak pressure of the cavitation bubble collapse initially increases and then decreases as γ increases. In-depth research on the collapse morphology and shockwave characteristics of cavitation bubbles near elastic boundaries offers theoretical support for harnessing cavitation bubble energy and selecting anti-cavitation erosion materials.
Year: 2025