ABSTRACT
As tidal turbine designs reach prototype and commercial deployment stages, interest has risen in the successful deployment of multiple turbines close together. Turbines in the same area risk interference with each other’s resource through various mechanisms: turbulent wakes impacting downstream turbines; increased thrust on the tidal flow reducing its mean velocity; or other more complex interactions with the marine environment (Vennell et al. 2015). The seabed bathymetry is also often complex in areas of high tidal energy density, posing additional challenges for developers when choosing where to place devices. Much work has therefore been done regarding tidal turbine arrays and appropriate spacings between turbines. A number of methods have been used to investigate these effects: computational fluid dynamics modelling has been carried out for arrays in relatively simple channel cross-sections, such as the work done by Malki et al. (2011) for a small number of devices, or that of Draper et al. (2013) for a long fence array near a headland. In general, due to the computational complexity of the problem, simpler models are employed when larger arrays, complex bathymetry or real ocean data are included: most considerations of real tidal basin sites to date characterise turbines as a simple additional bed friction term (Adcock et al. 2012).
