Validation of a turbulence numerical 3D model for an open channel with strong tidal currents

Turbulence characteristics of tidal currents, essential to predict the performance of tidal stream energy converters, present a significant spatial and temporal variability. Spatial fluctuations can occur within an area of the order of m2, mainly due to the geomorphologic characteristics of the area. Temporally due to ebb-flood asymmetries and also the effect of meteorological agents such as wind and waves, especially at shallower depths. This paper introduces an FVCOM (Finite Volume Community Ocean Model) numerical model validated with current velocity and turbulent kinetic energy data from three measuring devices installed in the Tanoura and Naru Straits (Goto Islands), one of them covering different vertical layers of the water column, confirming its capacity to estimate turbulence conditions at various depths when these are mostly generated by tidal currents. Correlation coefficients obtained under these conditions at the three locations are higher than 0.84 and 0.8 for current velocity and turbulent kinetic energy, respectively. Results from the validated model show that at deeper layers, TKE is primarily determined by the bathymetry characteristics of the area, while for middle and shallower depths the coastline shape is more important. (C) 2020 Elsevier Ltd. All rights reserved.