Abstract: Tidal current turbines represent core equipment in the development and utilization of ocean energy. To broaden the application of such turbines, the computational fluid dynamics (CFD) method is carried out to investigate three-dimensional numerical simulations of a novel fin-ring horizontal-axis hydrokinetic turbine. This turbine features an unconventional structural design, consisting of a central hub, 7 concentric rings and 88 fin plates. First, it tends to evaluate the hydrodynamic performance of the original design through numerical simulations, and verify the reliability of the numerical model against previously existing experimental measurements in literature. Then, a parametric analysis is focused on the two key design parameters of the fin plates (camber and angle of attack) to systematically examine the turbine's hydrodynamic performance with different combinations of these parameters and determine the optimal design. The results illustrate the combination of a camber of 10 mm and an angle of attack at 20°achieves the best balance between guiding efficiency and resistance loss, thereby significantly enhancing turbine performance. This optimal combination peaks with the power coefficient of 0.42 and a corresponding tip-speed ratio of 1.8. It is also demonstrated that the fin-ring turbine’s certain advantages in energy capture efficiency and eco-friendliness, compared to traditional horizontal-axis and vertical-axis turbines. This study elucidates the hydrodynamic characteristics of this turbine laying a quantitative basis for parameter matching, offering new insights for innovative tidal turbine designs.

Key words: tidal power, fin-ring horizontal axis hydrokinetic turbine, hydrodynamic performance, parameter optimization