Numerical Study of Performance of Horizontal-Axis Tidal Turbine with Different Configurations

Tidal stream turbines have the potential to produce considerable amount of clean renewable energy from ocean tides. To better understand the performance of tidal current turbine, this paper investigates the effect of configurations, such as hubs, support structures, and blade tips on performance of the horizontal-axis tidal turbines (HATT). To the end, a three-dimensional (3D) numerical model based on the k-ω SST model is applied to simulate a full-scale HATT with three blades, in which the set-up is identical to the experiments and the independences of several factors are considered. The results show that the form of the hub has a certain influence on the turbine performance. In addition, a well-designed fairing can lead to a higher power coefficient (CP). However, the influence of the support structure remains unclear. To minimize the wingtip vortices, an appended structure of the blade tip is designed, with which the turbine can extract up to 4.3% more energy in an appropriate working situation.