Experimental study of the influence of flexible boundaries with different elastic moduli on cavitation bubbles

Research on cavitation phenomena in various fields has shown that the mechanical properties of boundary materials have an important influence on the cavitation bubble. Here, an underwater low-pressure discharge method is used to induce a cavitation bubble, and a high-speed photography system is used to record the process of cavitation bubble collapse near different flexible boundaries. The results show that under a small elastic modulus, the cavitation bubble has a distinct mushroom shape during collapse. As the elastic modulus of the material increases, this shape evolves into a small cap and a large stalk until it disappears, thus increasing the critical condition of the bubble collapse to the boundary. There is a potential power relationship between the dimensionless deformation and elastic modulus. The dimensionless elastic modulus and distance can be used to determine whether a flexible boundary will be penetrated by a cavitation bubble. A cavitation bubble collapse shock wave near a flexible boundary will enter the boundary material with a propagation speed slightly slower than the shock wave velocity in the water body. Determining the collapse characteristics of cavitation bubbles near such flexible boundaries has important guiding significance for the utilization and prevention of cavitation near flexible boundaries.