One of the biggest challenges to tidal power development is the high cost attributable to conservative engineering of tidal energy converters (TEC's)1. This is due to a lack of understanding of tidal flows and in particular, of turbulence at high energy sites. Turbulence is known to affect turbine loading and power performance, however properly quantifying these effects remains a challenge.
Tidal site characterisation is usually based on methods inherited from the wind energy industry.2 However, this is not appropriate for tidal flows due to a number of differences such as: boundary layer considerations, blade sizes relative to the channel and additional complexities introduced by wave-current interactions, bathymetry and coastline geometries. Many wind turbulence models either have not been properly validated for tidal applications or have been found to be inadequate3.
To date, there have been few large-scale, operational TEC's to provide data, and due to the complex and chaotic nature of turbulent motion, simulations and modelling are challenging. The recent TEC's being tested in the field provide an opportunity for industry and academia to collaborate and use the field data to develop better methods for tidal turbulence characterisation.
This project will be carried out in collaboration with two industrial partners (EMEC and Orbital) and three universities (Edinburgh, Strathclyde and Exeter). The aim is to develop improved analytical methods for characterising tidal turbulence, using field data from Orbital's floating tidal turbine and other available datasets. The effects of turbulence on TEC loading and the sensitivities of various turbulence parameters will be analysed. Synchronous operational turbine data will be analysed to develop methods of relating turbine loads and power output to flow fluctuations and hence to turbulence parameters.