3D flow simulation of a circular leading edge hydrofoil and assessment of cavitation erosion by the statistical evaluation of void collapses and cavitation structures

Abstract

A simplified test case of a centrifugal pump blade, a hydrofoil with circular leading edge, is investigated. Cloud cavitation as a particularly aggressive type of cavitation is studied using a compressible 3D flow solver with barotropic cavitation model. The results are compared to measurement data for different Reynolds and cavitation numbers. The shedding frequency is well predicted. A statistical evaluation of a multitude of single collapsing voids is performed. Collapse frequency and magnitude of the pressure peaks are evaluated to obtain wall load collectives. Material damage on the hydrofoil suction surface obtained in erosion measurements is compared to the local flow aggressiveness distribution in the simulation. Erosion sensitive wall zones are identified in good agreement with measurement data. A relationship between cloud cavitation structures and erosion sensitive wall zones is demonstrated that enables a simple and approximate erosion assessment by 3D flow simulation.