An application of bubble collapse pulse height spectra to venturi cavitation erosion of 1100-o aluminum

Abstract

Venturi cavitation erosion tests were performed and correlated with bubble collapse pulse height spectra measured by a microtransducer. The effects of the throat velocity and the cavitation number σ (referred to the downstream pressure and throat velocity) on the erosion rate (MDPR) were studied. The velocity damage exponent was 4.11 for 0.62 ⩽ σ ⩽ 0.80, while the MDPR is almost independent of velocity for σ = 0.85. The MDPR decreases with increased σ for 0.62 ⩽ σ ⩽ 0.85. The data were reduced to “acoustic power” (from pulse height spectra) and “erosion power” (the ultimate resilience multiplied by the MDPR). A near-linear relationship was found between these. Their reciprocal ratio ηcav ≈ 7 × 10−11. For σ = 0.62, the data deviated from the others, possibly because of the work hardening of the eroded surface.