Abstract

Numerical simulation is done for the investigation of the free surface effect on the cavity shape of a hydrofoil in shallow water. The air- vapor-water three phases flow around the hydrofoil is resolved using the scale adaptive simulation (SAS) method. The two interfaces, i.e. the air-water free surface and the vapor-water cavitation interface, are tracked simultaneously by the volume of fraction (VOF) method, with the cavity shape modeled by the Schnerr-Sauer's cavitation model. One two dimensional validation case for the hydrofoil with thickness D=16mm in a tunnel is presented, and then the validated method is used to simulate the cavitation flows around the same hydrofoil oriented with several attack angles (Ak = 2°, 5° and 8°) under various water depths (H=0.07m, 0.10m and 0.13m). The foil's drag coefficients, total vapor volumes and the cavity shapes of these free surface cases are compared and analyzed.

Keywords:
cavitation, cavitation flow, free surface, peak value, free surface case, validation case, interface, water depth, simulation, cavity shape
Subjects:
Reservoir Fluid Dynamics
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2014. International Society of Offshore and Polar Engineers
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