Concept of Focusing of Collapse Energy- Application To cavitation Observations

Paper in proceeding, 2003

The concept of focusing of the collapse energy is well established for the case of collective collapse of cloud cavitation. It has been indicated however that erosion can also be generated by cavities that stay glassy until a very late stage of the collapse, a circumstance implying that focusing of energy should be analyzed also for this type of cavities. In this study, the concept of focusing of the collapse energy has been applied in practical observations as a procedure for analysis of erosive cavities. From some experiments, it was found that glassy cavities can, as focusing cavities, be closely related to the generation of severe erosion. A simplified cascading process of the focusing of collapse energy is also assumed for the glassy cavity. Furthermore, erosion tests results showed that any type of fluctuations in the focusing of the collapse energy lead to a decrease of the collapse pressure and thus a decrease of the erosion.