Simultaneous observation of cavitation structures and cavitation erosion

Despite a large ensemble of works on the relationship between the macroscopic cavitation structures and their erosive potential a study that would link individual cavitation events with specific damage has not yet been made. In the present study we attached a thin aluminum foil to the surface of a transparent Venturi section using two sided transparent adhesive tape. The surface was very soft-prone to be severely damaged by cavitation in a very short period of time. Using two high speed cameras we simultaneously recorded cavitation structures and the surface of the foil. Analysis of the results revealed that damage only occurs at cavitation cloud collapse, and that the size of the cloud and its distance from the wall at collapse do not influence the extent of the damage and that an irregular or “broken” type of cavitation cloud causes the most damage to the foil. Also and probably the most important part of the entire study shows the sequence where one can see the separation and the collapse of cavitation cloud and the corresponding appearance of cavitation erosion.