Simulating marine current turbine wakes with advanced turbulence models

Work is presented which compares the abilities of the Detached Eddy Simulation turbulence model to a Reynolds- Averaged Navier-Stokes turbulence model, for CFD simulations of a horizontal axis tidal turbine under different ambient turbulence conditions. Comparisons are made of the abilities of the respective models to predict both performance characteristics as well as wake length and character. It is demonstrated that whilst Detached Eddy Simulation holds little advantage over a k-! SST model for predicting mean performance characteristics, significant advantages are shown when predicting wake length, as well as allowing the prediction of the magnitude of fluctuations. It is expected that, despite the higher computational expense, hybrid LES-RANS turbulence models such as Detached Eddy Simulation will be of interest to engineers designing arrays of tidal turbines, which are anticipated if tidal energy is to make a significant contribution to the world’s energy resources.