Experimental and numerical study of a vertical axis tidal turbine performance

In the present study, a vertical axis tidal turbine with movable blades was investigated using experimental and numerical methods. A laboratory model of this turbine type nominated as Hunter turbine was manufactured and tested in an established test rig. In the next step, 3D steady Reynolds-Averaged Navier-Stokes (RANS) equations were solved by CFD using k-ω turbulence model to predict turbine's performance. The numerical results were verified by the experimental data. In addition, effects of duct, neighbor turbines distance and layout on the power coefficient were investigated. The results showed that the power coefficient of a turbine in the present of ducts with area ratios of 0.1-0.26 increased from 0.14 to 0.29. It was also observed that in a four-turbine farm, the output power is maximum for a distance of 13D (diameter of turbine) between neighbor turbines and area ratio of 0.26. For this case, the farm's performance factor is 0.944.