Three-dimensional modelling of suspended sediment transport in the far wake of tidal stream turbines

• Published in: Renewable energy 2020-05, Vol.151, p.956-965
• Main Authors: Li, Xiaorong, Li, Ming, Amoudry, Laurent O., Ramirez-Mendoza, Rafael, Thorne, Peter D., Song, Qingyang, Zheng, Peng, Simmons, Stephen M., Jordan, Laura-Beth, McLelland, Stuart J.
• Format: Article
• Language: English
• Subjects: Additional shear stress; Mixing enhancement; Suspended sediment transport; Three-dimensional modelling; Tidal stream energy
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2019.11.096

A three-dimensional tidal turbine simulation based on an oceanographic numerical model has been tested for suspended sediment calculation, particularly in the wake of a standalone tidal turbine. The results suggest a need for further improvement of the model in order to obtain correct predictions of suspension strength of the wake and suspended sediment concentration under the influence of a turbine (compared to measured data). Due to the wide use of FVCOM in coastal applications where turbines are commonly installed, it proves necessary to address this issue. Two approaches with respect to modifying bed shear stress and turbulent mixing calculations in the presence of a turbine are proposed and tested in this research. Using data collected in the laboratory as reference, the turbulent mixing enhancement approach is shown to be effective. A series of tests are carried out to identify the impact of the turbine on suspended sediment transport in its vicinity. The results suggest that the impact is highly dependent upon the sediment grain size. •A 3D tidal turbine simulation system is tested for suspended sediment calculation.•The system includes 3D representation of tidal turbine effects on flow structure and turbulence.•The system requires modification to produce accurate sediment suspension strength of the wake.•A turbulent mixing enhancement approach is shown to be effective.•The impact of turbine on suspended sediment transport is shown to depend on sediment grain size.