Free surface effects and the utility of a skim plate for experiments in a water towing tank at steady and unsteady model velocity

Abstract A towing tank is utilized to investigate the flow field around a two-dimensional submerged foil model operating near free surface. Free surface effects are analyzed for steady and unsteady velocity. The model’s submergence depth angle of attack varied. Tests conducted facing upside-up upside-down. deflection recorded experimental results validate an analytic that deployed predict wake wave patterns at arbitrary mechanism leading load alterations when in vicinity explored detail using results. imposed wave-induced velocity perturbations alter effective experienced by foil. Flow separation delayed promoted For test cases with sinusoidal velocity, forward traveling waves generated, time-varying change inflow condition Increasing alleviates effects. skim plate installed in-between model. It shows similar alleviating as obtained increasing locally blocking velocities. position varied longitudinal direction determine its most advantageous position. Surface alleviated effectively protrudes upstream Graphical abstract