Unsteady wake modelling for tidal current turbines

Modelling a Tidal Turbine in Unsteady Flow

A brief review of the literature is provided on the characteristics of marine currents and the approaches used for simulating tidal turbines. The feasibility of using CFD models to simulate time-dependent turbulent flow around a tidal turbine is then explored. Two different approaches for specifying the structure of the turbulent inflow conditions in CFD models are compared: the von Kármán spec...

Unsteady Flows in Turbines

Accuracy of the actuator disc-RANS approach for predicting the performance and wake of tidal turbines.

The actuator disc-RANS model has widely been used in wind and tidal energy to predict the wake of a horizontal axis turbine. The model is appropriate where large-scale effects of the turbine on a flow are of interest, for example, when considering environmental impacts, or arrays of devices. The accuracy of the model for modelling the wake of tidal stream turbines has not been demonstrated, and...

A large-eddy simulation study of wake propagation and power production in an array of tidal-current turbines.

This paper presents our initial work in performing large-eddy simulations of tidal turbine array flows. First, a horizontally periodic precursor simulation is performed to create turbulent flow data. Then those data are used as inflow into a tidal turbine array two rows deep and infinitely wide. The turbines are modelled using rotating actuator lines, and the finite-volume method is used to sol...

Flow Misalignment and Tidal Stream Turbines

Extensive Research and Development (R&D) within the tidal energy industry is pushing this sector towards commercial viability, with full scale prototypes starting to meet the challenges of the marine environment. This paper combines velocity data collected from Ramsey Sound (Pembrokeshire, Wales), with Computational Fluid Dynamics (CFD) to assess the impact of non-rectilinear flows on turbine r...