Cavitating Flow Past a Large Aspect-Ratio Hydrofoil

Abstract

Tip effects on the cavitating flow past a large aspect-ratio lifting hydrofoil are considered. The tip vortices arising from the flow leakage around the tip from the lower to the upper side of the hydrofoil are assumed to cavitate. The flow over the central section of the hydrofoil is taken as two-dimensional cavity flow and hence there is a wide planar cavity there. The separate cavity regions are taken not to coalesce. The flow is represented by a simple horseshoe-vortex model and descriptions of the flow over the central section, near the tip and well downstream, are derived and appropriately matched. The lift on the hydrofoil is then calculated, taking the downwash into account. The lift is seen to be reduced by the tip effects, and shows good comparison with experimental results.