Experimental investigation of bow-mounted passive and active hydrofoils for ship resistance reduction in regular waves

This study experimentally investigates the influence of passive and active bow-mounted hydrofoils on ship-resistance reduction and thrust generation in regular waves. Towing-tank experiments were performed on a Series 60 ship model equipped with both passive and active hydrofoils to quantify their effects on the total resistance. The active hydrofoil system, actuated by a servomechanism, was continuously adjusted in angle of attack in synchronization with the bow's vertical motion, whereas the passive hydrofoil was kept at a fixed angle of attack of zero degrees. Tests were conducted over various forward speeds, wavelength-to-ship-length ratios, and active-hydrofoil oscillation amplitudes to evaluate the influence of these parameters on hydrodynamic performance. The results indicate that the active hydrofoil generated a notable propulsive thrust, achieving up to a 32 % reduction in the mean total resistance compared with the passive configuration. These findings emphasize the superior energy-harvesting potential of active hydrofoils and their promise for reducing ship power demand and fuel consumption. The results support the design and control optimization of wave-interaction devices for ships.