Constructive interference effects for tidal turbine arrays

The performance benefits of deploying tidal turbines in close side-by-side proximity to exploit constructive interference effects are demonstrated experimentally using two 1.2 m diameter turbines. arrayed at 1/4 tip-to-tip spacing, and their compared with that a single rotor. Tests were completed the 25 diameter, 2 deep wave current FloWave Ocean Energy Research facility. A detailed assessment inflow conditions different control points is used understand impact rotors, designed for high blockage conditions, have on approach flow. After accounting global blockage, 10.8 % uplift twin-turbine-averaged power coefficient, relative turbine, found turbine design speed, expense 5.2 increase thrust coefficient 3.1 tip-speed-ratio. Flowfield mapping flow array device scale including bypass flows jetting between Azimuthal variation blade root flapwise edgewise bending moments show interact beneficial manner, additional sustained loading peaks as blades pass neighbouring Peak twin occurred higher tip-speed-ratio than which consistent exerting achieve maximum power. be more gradual turbine. Using differential rotor speed we observe robust small differences operating point. Through these experiments demonstrate there substantial, achievable benefit from closely arraying operation designing them interference.