CFD analysis of hydrodynamic loadings on tidal turbines under wave conditions

With greater reliance on renewable energy, tidal energy has attracted increasing attention due to its enormous potential and advantage in terms of predictability. In the nearly 20-year design life, tidal turbines must be capable of contending with the harsh submarine conditions, however, many existing studies revealed that during operation, the tidal turbine experiences frequent and large-scale fluctuations of cyclic loads of tides and waves especially when effected by surface waves, which may lead to blade fatigue damage. Therefore, in this paper, a Computational Fluid Dynamics (CFD) analysis of the performance of tidal turbines and the fatigue loading evaluation under wave conditions have been conducted. In the work, the inlet velocity profile method is adopted to produce waves and a stationary scaled tidal turbine numerical model has been simulated to study the fluctuation of the hydrodynamic loadings on the turbine and the blades. In addition, a series of different porous plates are placed in the flow field to explore the blockage effect of the tidal turbine. The results gained from the numerical simulations are projected to be compared and validated with a range of scheduled hydrodynamic tests in the wave tank at the University of Galway. This study aims at providing the literature with a better understanding of the operating performance and fatigue damage mechanism of tidal turbines under wave conditions. This study will support the development of tidal energy, while helping Irish society achieve Net-Zero emissions by 2050.