Blockage Corrections for Tidal Turbines—Application to an Array of Turbines in the Alderney Race

Tidal turbines are located in shallow water depths comparison to their dimensions (15 m-diameter 40 m depths, typically). Constrained vertically by the depth and laterally neighbouring turbines, flow within a tidal farm is subjected blockage effects that influence performance of individual devices. The Betz limit (which maximum power extractable from an unconstrained flow) can, therefore, be exceeded as demonstrated Garrett Cummins. Thus, beyond significant ratio, should considered when assessing energy production farm. actuator disk method particularly suited simulate field array under realistic conditions. However, implementation disks coastal numerical models relies on relationships neglect thrust We propose here formulation corrected integrate these effects. This modified formulation, based model Whelan et al., integrated into regional three-dimensional Telemac3D targeted towards Alderney Race (English Channel). applied two hypothetical farms with aligned staggered arrangements, respectively. Blockage corrections coefficients found have counterbalanced production. Thrust correction results noticeable reduction array. associated decrease increase turbine coefficient. were, result slight increase, 3%, over mean spring cycle.