Prediction of Cavitation Damage

A non-dimensional number called cavitation damage number has been proposed, based on the concept of dynamic indentations produced by short range shock - waves due to the collapse of the cavitation bubbles. This number gives the ratio of the energy absorbed by the material in deformation to the energy of the collapse of the bubble. The cavitation damage number has been correlated with the number of cavities collapsing in a given period. The present concept adopted explains most of the experimental observations made by various research workers in this field. (A few of them being the threshold velocity for the inception of damage, incubation period, effect of time, effect of corrosion, and so on.) Experiments show that it is possible to predict the eroded length, breadth, and area if the geometry of the cavitating body and the value of the cavitation parameter are known . These results indicate the possibilities of predicting possible cavitation damage and thus aid in the proper choice of the material for fabricating any hydraulic machine or a structure.