Numerical Simulation of Wind Turbine Wakes based on Actuator Line Method in NEK5000

Abstract: Nowadays wind turbines are clustered in wind farms and the wake development plays an important role in energy production and blade fatigue load of tubines. The actuator line method is an effective modeling approach that gives improtant wake flow characterstics of a wind turbine. In the last few years, numerous studies have been conducted based on this method using Ellipsys3D, a computational fluid dynamics (CDF) flow solver based on finitie volume approach. However, due to the limited order of accuracy of this solver, it is not capable of a linear stability analysis with small amplitude of perturbation. Therefore, the present work investigates implementing the actuator line ethos into a  high order method, Nek5000, a flow solver based on the spectral element approach. The main goal of the present work is to validate the code implementation by comparing the simulations results with the previous Ellipsys3D data. Both 2-D and 3-D Gaussian distribution functions are discussed for the actuator line force distribution. Parametric study is carried out regarding the smoothing parameter ε and the partitioning of the actuator line.