Abstract: Surface waves are a significant contributor to the unsteady blade loads for tidal turbines. Their relative effect is dependent on a range of site and device specific parameters. Using a combination of theory and simulations, for both regular and irregular wave conditions, this paper demonstrates that the wave height, period, direction and hub height relative to the surface are key drivers of the blade loads. The channel depth will also affect the loading induced by long period waves. Waves can alter the dominant periodic load and also enhance the turbulence induced loads, which can have severe implications on the fatigue life of the blade. The findings will aid turbine developers in assessing the long term loading of their device.
