Full Downwind Turbine Simulations Using Actuator Line Method

In the present work the actuator line (AL) technique is proposed to model a complete wind turbine (rotor and tower) in downwind configuration. The case study used is the Unsteady Aerodynamics Experiment (UAE) Phase VI turbine to analyze its suitability in capturing the tower shadow effect. Computational Fluid Dynamics (CFD) simulations were carried out using the open-source code OpenFOAM and the class of horizontal wind turbine AL from the toolbox SOWFA developed by the National Renewable Energy Laboratory (NREL). The objective of the present work is to validate the use of AL model for tower simulations and to establish whether such simplification is valid to capture the effect that tower shadow exerts over the rotor aerodynamics and to verify the accuracy of the proposed model regarding prediction of loads in the rotor. Computations were done first on an isolated rotor modelled with the AL technique; second on a full downwind turbine with AL in both rotor and tower; and, finally, on a 3D rotor with AL tower. Numerical results show good agreement with the experimental data concluding that the AL model is capable of a fast and accurate load prediction under certain conditions.