Tidal Basin Hydrodynamics

BCThe group is conducting research to understand how much tidal power can be extracted from a variety of coastal basins and what effect power extraction will have on the natural hydrodynamics within these basins. The group is using both analytical and numerical modelling to investigate this, both for idealised geometries and for possible sites for tidal energy extraction around the United Kingdom.

Axial Flow Devices

flowave_3Tidal stream turbines operate in constrained flows where the close proximity of the seabed, sea surface, and neighbouring turbines has a significant effect on turbine performance, through a phenomenon known as blockage. We employ analytical, numerical and experimental modelling to understand the effect that blockage and realistic conditions of the underwater environment have on the performance of axial flow tidal energy converters. Theory indicates that turbines designed to exploit the constructive interference effects that arise in high blockage conditions may see a significant uplift in the efficiency of power extraction compared to wind turbines. We have developed turbine designs to exploit these effects, which have been validated in two experimental campaigns in FloWave (February 2019) and SSPA (September 2019). In addition to specific turbine designs, we are interested in improving the understanding of the hydrodynamics for turbines generally, and work closely with the wind power group in this area.

Advanced Turbine Concepts

pitch_controlTidal stream turbines are deployed environments subject to a range of challenging conditions including significant levels of turbulence, strong shear profiles and waves. The flow approaching a short fence of turbines will vary across the fence due to the array-scale bypass flows, resulting in cross-fence performance variation. Turbines deployed on floating platforms will operate in the wave zone and likely experience platform-induced flow variations which may contribute significantly to unsteady loading. We employ numerical and experimental approaches to investigate these phenomena and explore techniques to mitigate their consequences for turbine performance.