VALIDATION OF HYDROFOIL DESIGN PROGRAM HYF3

To estimate the resistance of hydrofoil craft during the transition speeds from hull to foil borne speeds, a hydrofoil design program (HYF-3) has been developed. HYF-3 solves the system of equation for the lift and drag of the hull and hydrofoils at the equilibrium trim and foil submergence. HYF-3 calculations are made for conditions corresponding to experiments with a 4.27m jon-boat fitted with submerged foils and the IPT hydrofoil experiments with surface piercing foils. The HYF-3 program estimates are in excellent agreement with the measured resistance for both cases.