Cavitation and cavitation damage

Abstract

This thesis deals with the study of certain aspects of cavitation damage. In the first part of the thesis, a critical survey of the existing literature has been made, and various theories of cavitation damage have been discussed. In the second part, the results of experiments conducted to study the effect of different properties of construction materials are reported. The relationship between cavitation damage and various factors such as water–cement ratio, curing time, cement–aggregate ratio, admixtures, and the grading of aggregates is analysed. Of all the factors studied, the compressive strength of the material appears to be the governing factor. Investigations on surface roughness and the time?rate of cavitation damage provide insight into how far this damage can be eliminated or reduced to a great extent. Further studies on the effect of hydrodynamic factors on cavitation have also been reported. A correlation has been established between flow velocity and cavitation damage for a particular shape of cavitating body. A non?dimensional cavitation damage number has been suggested for correlating cavitation damage irrespective of the size or shape of the cavitating body. For geometrically similar bodies, the Reynolds number has been correlated with the rate of cavitation damage. A detailed study of the cavitation damage zone is also reported. These studies suggest a new approach for predicting cavitation damage in prototypes from model studies.