Experimental research on tidal current vertical axis turbine with variable-pitch blades

Due to the limited storage and ever-increasing dependence on fossil fuel, the world is in the phase of shifting toward renewable energy. Tidal current energy is one of the most predictable forms of renewable energy, which is harnessed by utilizing a tidal current turbine. To study the performance of the tidal current turbine relating to the ability of energy absorption and exchanging, experimental tests play an important role which can not only validate the numerical results but also provide a reference for the prototype design. In this study, a series of experiments related to vertical-axis turbines (VAT) were carried out at Harbin Engineering University and a large quantity of experimental data to study the hydrodynamic performance of turbines was presented. Based on the different techniques used to control the pitch mechanism, the experiments can be classified as the cycloid type controllable-pitch, spring-control pitch and passive variable-pitch VAT experiment. The influences of the different parameters on the hydrodynamic performance of turbines were discussed. Finally, some control strategies for the blade for different turbines were given.