Under real sea conditions, floating vertical-axis tidal turbines experience motions in six degrees of freedom which influence the relative velocity perceived at the turbine's blades, with a direct effect on the loading and performance of the rotor. Understanding the fluid-structure interaction of a vertical-axis tidal turbine under the floating carrier’s motions provides insights about critical aspects for the design of floating hydrokinetic systems.
In this project, the TU Delft in-house U2DiVA code is indicated as a conservative and time-effective tool to assess the hydrodynamic response of a vertical-axis tidal turbine under surge, sway and yaw motions compared to the computational fluid dynamics approach commonly used in the scientific literature. The effect of surge motion on the fluid-structure interaction of two existing vertical-axis tidal turbines is investigated using U2DiVA. The analysis focuses on the details of the time evolution of the flow field perceived at the blades and on the modified cyclic loading and power extraction when given surging conditions are imposed.