Influence of the Nuclei Size Distribution on the Collapsing Behavior of the Cloud Cavitation

Dynamics of a spherical bubble cloud with nuclei size distribution is investigated numerically when the surrounding pressure is decreased from 50kPa to 10kPa and then increased to 50kPa stepwisely. A set of governing equations for the motion of bubble cloud are formulated combining the averaged equation and the equation of bubble motion with emphasis on the internal phenomena of each bubble. The nuclei size distribution has significant effects on the cloud dynamics in comparsion with the results for mono-dispersed cloud. When the cloud contains multi-dispersed bubbles in their size, the maximum pressure in the bubbly mixture becomes lower than in case of mono-dispersed cloud. however, the maximum pressure emitted from each bubble has the same order for both cases. The range where high-emitted pressure is observed is wider than in mono-dispersed cloud.