Modelling Deep Green tidal power plant using large eddy simulations and the actuator line method
Journal article, 2021

The Deep Green technique for tidal power generation is suitable for moderate flows which is attractive since larger areas for tidal energy generation hereby can be used. It operates typically at mid-depth and can be seen as a “flying” kite with a turbine and generator attached underneath. It moves in a lying figure-eight path almost perpendicular to the tidal flow. Large eddy simulations and an adaption of the actuator line method (in order to describe arbitrary paths) are used to study the turbulent flow with and without Deep Green for a specific site. This methodology can in later studies be used for e.g. array analysis that include Deep Green interaction. It is seen that Deep Green creates a unique wake composed of two velocity deficit zones with increased velocity in each wake core. The flow has a tendency to be directed downwards which results in locally increased bottom shear. The persistence of flow disturbances of Deep Green can be scaled with its horizontal path width, Dy, with a velocity deficit of 5% at approximately 8–10Dy downstream of the power plant. The turbulence intensity and power deficit are approximately two times the undisturbed value and 10%, respectively, at 10Dy.

Large eddy simulations


Tidal power

Actuator line method


Sam T. Fredriksson

University of Gothenburg

Göran Broström

University of Gothenburg

Björn Bergqvist


Johan Lennblad


Håkan Nilsson

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Renewable Energy

0960-1481 (ISSN) 18790682 (eISSN)

Vol. 179 1140-1155

Driving Forces

Sustainable development

Innovation and entrepreneurship

Subject Categories

Energy Engineering

Fluid Mechanics and Acoustics

Marine Engineering

Areas of Advance



C3SE (Chalmers Centre for Computational Science and Engineering)



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