Investigations into the ventilated cavities around a surface-piercing hydrofoil at high Froude numbers

This study investigates the ventilated cavities around a surface-piercing hydrofoil, aiming to extend previous studies by an in-depth understanding of vaporous cavity behaviors and flow-regime transition at high Froude numbers. An experiment is carried out in constrained-launching water tank with vertically cantilevered hydrofoil piercing still surface. The recorded using high-speed photography, maps are summarized over broad range number yaw angle different immersed aspect ratios. In addition well-known steady flow regimes (i.e., fully wetted flow), unsteady cavitating revealed very small angle, which exhibits cavitation shedding dynamics behaviors, including growth, destabilization, collapse. from attributed vapor-cavitation-induced ventilation besides tip-vortex-induced ventilation. Vaporous promotes formation, but it has meet criterion that air should enter sub-atmospheric through tip-vortex path before length reaches maximum. Moreover, improved lifting-line model developed considering effects free surface finite ratio. Both analytical modeling experimental measurements reveal follows power relation against parameter. Such knowledge lays foundation for design optimization control strategy hydrofoils.