Cavitation erosion tests on a 2D hydrofoil using surface-mounted obstacles

A new cavitation erosion testing procedure in high-speed cavitation tunnel is presented. The method is based on surface-mounted obstacles on a plane-convex hydrofoil leading edge. This experimental set-up is able to accelerate the accumulation of damage on specimens located behind the obstacles and presents several advantages. Measurable cavitation erosion damage has been obtained for a thermal spray coating and a stainless steel 13.4 after 75 h of operation. The hydrodynamic operating conditions have been an inlet flow velocity of 35 m/s, a sigma value of 1 and an incidence angle of 3°. Final erosion results have been compared with similar data obtained with the vortex cavitation generator (VCG) and the vibratory apparatus as a continuation of a previous study, see [Wear 233–235 (1999) 65]. The cavitation induced vibration monitoring provides a way to explain the apparent discrepancy of the erosion data between the tests with the high-speed cavitation tunnel and the vibratory apparatus.