Pulse pressure loading and erosion pattern of cavitating jet

Various erosion patterns generated through the cavitating water jet impacts under ambient pressure conditions were investigated in experiments and numerical simulations. A series of normalized stand-off distances ls/do ∈ [2.5 13.5] were studied during the erosion acceleration period. Two ring-like erosion areas were observed for comparatively low ls/do ∈ [2.5 6.5]. To gain insight into the pulse pressure loading on the erosion area, numerical calculations were performed using the volume of fluid (VOF) interface capturing methodology combined with the large-eddy simulation turbulence model. The erosion patterns are clarified based on the mass loss and distribution features of the eroded regions. The first ring, generated by the cavitation clouds impingement outside the central stagnation area, mainly contributes to the mass loss. The second ring moves inward, merges into the inner ring and eventually vanishes with increasing ls/do. High pressure pulsation is found around the locations of the maximum erosion and the approximate intermediate radius of the second ring. The pressure pulsation in the first ring area are dominated by the frequency of the vortices shedding from the jet nozzle. Several higher frequencies are found as the spectral features of the eroded regions in each pattern.