The first objective of this work is to numerically investigate how the proximity to the free surface influences the hydrodynamic response and susceptibility to cavitation of a hydrofoil undergoing controlled pitching oscillations, for high-speed full-scale operating conditions. A second objective is to develop a time-domain Reduced Order Model (ROM) to predict the unsteady hydrodynamic loads (for rapid exploration of the design space and for real-time active/passive actuation/control). The ROM delineates the fluid-structure interaction (FSI) forces into fluid inertial, damping, and disturbing force components, and only predicts the primary oscillation frequency. In addition to predicting the unsteady loads, when coupled with the solid equations of motion, the ROM can also be used to calculate the natural resonance frequencies and damping characteristics with consideration for viscous and free surface effects. This will allow designers to better predict and control the dynamic response of lifting surfaces operating near the free surface.
A Reduced-Order Model for an Oscillating Hydrofoil Near the Free Surface
Kennedy, Rory C., Helfers, Dillon, and Yin Lu Young. "A Reduced-Order Model for an Oscillating Hydrofoil Near the Free Surface." Paper presented at the SNAME 13th International Conference on Fast Sea Transportation, Washington, DC, September 2015. doi: https://doi.org/10.5957/FAST-2015-062
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