Abstract
The paper introduced a new concept to capture ocean energy from an offshore wind farm. The principal idea is to utilize an oscillating hydrofoil connecting the existing underwater tower of an offshore wind turbine. A proper motion of the hydrofoil is defined such that the tidal current energy from the vortical flow behind the underwater tower can be effectively captured. Based on the offshore wind resource and the existing wind farm layout, the proposed hybrid energy capturing device can effectively utilize the additional tidal current energy without requiring too much extra cost and ocean space. The physical model of the ocean energy capture system was conceptually developed. In order to track the maximum power efficiency, more comprehensive analysis was carried out by using the Lattice Boltzmann Method with Large Eddy Simulation, which includes the combined effects of different hydrofoil motion parameters such as the effect from heave amplitude, pitch angle and hydrofoil chord length. The overall efficiency of the offshore wind farm is improved with the oscillating flow generator. It is also found that the existence of the oscillating flow generator can effectively reduce the drag force on the wind turbine tower, which implies longer life time of the wind turbine system.