Intensity of Cavitation Damage Encountered in Filed Installations

Abstract : A nomogram called Cavitation Damage Intensity Estimator is presented for estimating cavitation damage intensities of field installations. This simple approach is based on an earlier definition of cavitation damage intensity as the power absorbed per unit area of the eroded material. Using this estimator and the data published for field installations, the damage intensity is estimated for ships' appendages, ships' propellers, valves, Diesel engine cylinder liners, hydraulic turbine runners and pumps. These estimates show that the intensities for propellers and valves can be several orders of magnitude higher than that for laboratory test devices. A summarized analysis shows the field experience and laboratory experience in the proper perspective in terms of their intensities. The possible usefulness of various protection methods are projected for various intensity levels. The threshold intensity of cavitation damage is found to be proportional to the endurance limit of metals. These ideas are only preliminary in nature and further coordinated field and laboratory efforts are suggested in this direction.