Abstract
Three numerical models were developed to explore the effect of regular wave propagation at different angles to the current flow (0°, 45° and 67.5°), without the presence of a turbine. The flow conditions generated by each of the wave-current models were analysed and used to estimate the impact of these flow conditions on Tidal Stream Turbine loadings and performance. It was found that as the wave angle deviates away from the current flow direction, the dominant current velocity starts to affect the angle of the individual velocity components as well as the overall direction of wave propagation from the inlet. The presence of waves in all three configurations was found to have no effect on the average velocity components, while previous validation found following waves and current also had no effect on the average performance of the turbine. Therefore, it is hypothesised that oblique wave-current conditions would also not affect the average performance of the turbine but will need further verification. Oblique wave motion will produce smaller cyclic fluctuations in the turbine loadings in comparison to following wave-current conditions as the wave motion is split across two directions and not just in a single direction. This multidirectional loading of the turbine will lead to more complex loading mechanisms which will impact design considerations for Tidal Stream Turbines exposed to oblique wave-current climates.