Experiments on the mean and integral characteristics of tidal turbine wake in the linear waves propagating with the current. (1st February 2019) - Zang, Wei
Abstract: The vast majority of tidal-stream sites have been described with turbulent flows coexisting with waves, but the wake of a tidal-stream turbine in such flows is not fully understood. A model tidal-stream turbine, of diameter 0.49 times the water depth, was tested under the influence of intermediate waves following the current, to analyze both of its mean and integral wake characteristics. An ambient intensity around 10% was established in the recirculating water flume. Acoustic doppler velocimeter (ADV) with Nortek Vectrino profiler probes were used to obtain the time-varying velocities, the turbulence intensities and the integral time scale. Analysis of velocity deficit indicated the mean wake and Gaussian distribution were consistent, with waves being of no real consequence on the wake recovery. The turbulence intensity was shown to be affected by the wave height for the upper region, and the influence of the wave period was greater for the integral time scale than for the wave height at the far-wake region. We believe these results offer significant insight into the turbine wake in a wave-turbulence flow.