Numerical modelling of combined wave, tidal current and turbulence interaction at tidal energy sites in the Fall of Warness, Scotland

Results are presented from a 3D coupled wave and tidal current numerical model applied to a tidal energy site in the Fall of Warness, Orkney waters, Scotland. The aim of this study is to develop a coupled 3D wave and tidal flow model and examine its accuracy in predicting wave-current interactions and associated turbulence parameters. The MIKE 21/3 software suite is used for modelling waves and currents. Field data obtained at the Fall of Warness using an Acoustic Doppler Current Profiler (ADCP) are used for model validation. Predicted tidal elevation, tidal flow velocities, flow directions, significant wave height, peak and mean wave periods, peak and mean wave directions, turbulence kinetic energy, dissipation of turbulence kinetic energy, eddy viscosity etc., are compared against measured data where possible. The results demonstrate that the coupled model works well in predicting wave-current interaction parameters. It should however be noted that the results presented here are for a period of low wave activity, and further work is required to better quantify and hence understand the behaviour of relatively high waves at sites in the Fall of Warness.