Analysis of long distance wakes behind a row of turbines _ a parameter study

The Science of Making Torque from Wind 2014

Eriksson, O.^1 ; Nilsson, K.^1 ; Breton, S.-P.^1 ; Ivanell, S.^1

Wind Energy Campus Gotland, Dep. of Earth Sciences, Uppsala University, Visby, 621 67, Sweden^1

关键词: Actuator disc concepts;    Atmospheric conditions;    Navier-Stokes solver;    Parameter studies;    Sensitivity to parameters;    Turbulence characteristics;    Turbulence intensity;    Turbulence level;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/524/1/012152/pdf
DOI  :  10.1088/1742-6596/524/1/012152

来源: IOP

【 摘 要 】

Large Eddy Simulations (LES) of the long distance wake behind a row of 10 turbines are conducted to predict wake recovery. The Navier-Stokes solver EllipSys3D is used in combination with the actuator disc concept. Neutral atmospheric conditions are assumed in combination with synthetic turbulence using the Mann method. Both the wind shear profile and turbulence are introduced into the flow field using body forces. Previous simulations using the same simulation method to model the Horns Rev wind farm showed a higher wake recovery at long distances compared to measurements. The current study investigates further the sensitivity to parameters such as the grid resolution, Reynolds number, the turbulence characteristics as well as the impact of using different internal turbine spacings. The clearest impact on the recovery behind the farm could be seen from the turbulence intensity of the incoming flow. The impact of the wind shear on the turbulence intensity in the domain needs further studies. A lower turbulence level gives slower wake recovery as expected. A slower wake recovery can also be seen for a higher grid resolution. The Reynolds number, apart from when using a very low value, has a small impact on the result. The variation of the internal spacing is seen to have a relatively minor impact on the farm wake recovery.