Research on the end-plate for vertical axis tidal current turbine

Abstract

Tidal current energy is one of the competitive alternative energy resources. Vertical axis turbine is the technology to extract energy from tidal current with some unique advantages. As the energy efficiency of vertical axis turbine is still relatively low, a blade tip device named end-plate is studied to improve the turbine’s performance. The end-plate was intended to block the fluid from flowing across the tip and the shape of the end-plate was designed according to the influence area of the tip flow. The comparison of the turbine with and without end-plates was made by numerical and experimental methods. Good agreement was achieved, and the result showed that adding end-plates on the tip of the blade could increase the turbine’s output power. On the basis of the former study, two kinds of end-plate enhancement were presented as inward-half end-plates and outward-half end-plates. The numerical research showed that both inward-half end-plates and outward-half end-plates had better output than the original end-plates. The numerical results also indicated that the blade with outward-half end-plates had the minimum amplitude of the torque over one rotational cycle among the three kinds of end-plates, while the blade with inward-half end-plates had the maximum amplitude of the torque. To obtain better power output and prolong the service life of turbine, the outward-half end-plate is recommended.