回転円板法で発生するキャビテーション・エロージョン

抄録

Cavitation erosion generated in a rotating disk device was studied through observations of eroded surface and mass loss measurements using Cu, Al and mild steel. By comparing the number and size of erosion pits occurring at the initial stage with those in a vibratory device, we found that the generating frequency of large collapse pressure that forms a pit was very small in a rotating disk device. This means that erosion proceeds due to surface fatigue in such a way that the surface first deforms and the fractures by the repeated action of the small collapse pressures below the critical pressure which forms impulsively a pit. The variations of the mean depth penetration rate (MDPR) as a function of velocity and cavitation number are shown for Cu. Al and mild steel and their differences in the materials are discussed.