NEAR-WAKE MEASUREMENTS OF A YAWED TIDAL TURBINE

Abstract:

In recent years, tidal stream turbines (TST) have made significant advancements towards commercialization with several full-scale deployments across Europe and the USA. It is common for TST to experience yawed inflow either due to wave-current interaction at the deployment site or artificially induced yaw to steer the wake away from downstream turbines on a farm. We will present near-wake Acoustic Doppler Velocimetry (ADV) measurements from laboratory experiments using a 1:20 scale three-bladed, constant chord, untwisted tidal turbine rotor. The turbine model was tested in a uniform inflow at yaw angles of 15° and 0° (baseline case). Wake data is collected at hub height up to a downstream location of 4D; the wake will be characterized in terms of flow statistics such as velocity deficit, turbulence intensity, anisotropy, skewness, and kurtosis. Additionally, disruption to coherent flow structures, like tip vortices, will be identified using spectral analysis of the wake.

Acknowledgments: The authors thank the US National Science Foundation for financial support for this project (Award #1706358, Fluid Dynamics Program).