The Effect of Blades on Hydrodynamic Performance of Half-rotating Impeller Tidal Turbine

The half-rotating impeller tidal turbine (HRITT) is a novel tidal current turbine of combined lift and drag, which has the characteristics of high power and good start-up performance. The hydrofoil of turbines plays a vital role in the design of blades on vertical axis tidal turbines (VATTs), which have practical value for improving hydrodynamic performance. Based on the analysis of the law of moving blades on a half-rotating impeller (HRI), the design requirements of the hydrofoil of the blades on the HRITTs were put forward in this paper. Then, the effects of three kinds of hydrofoils and their thicknesses on the average power coefficient and output power stability of the HRITTs were analyzed by numerical calculation. The results showed that the rhombic hydrofoil of blades had better output power performance than the rectangular hydrofoil and the elliptical hydrofoil of blades on the HRITTs. The thickness of hydrofoils had a great effect on the power coefficient and the stability of the output power of the HRITTs.