A Practical Approach in the CFD Simulation of Off-shore Wind Farms through the Actuator Disc Technique

In this work a practical approach to Computational Fluid Dynamics (CFD) simulations in wind resource evaluation is proposed in a test case of the IEA project (task 31) “Wakebench” focused on the benchmarking of wind wakes models. The proposed method uses an easy wake model, the Actuator Disc (AD), in a CFD approach, in order to understand the wind behavior in a complex wind farm of 18 turbines sited in the northern part of Netherlands, with a sustainable computational load. In order to optimize the simulation results a useful tool that automates the parameters evolution was developed; such tool is able to improve the control of the engineering parameters and is useful to prepare advanced post processing. The study was mainly focused on the analysis of the single wake; also simulations on the double wake case and other tests on larger wind farm were performed with success using the same automatic approach. Results are in quite good agreement with experimental data and the differences between the predicted and experimental results are to be addressed to: global effect of stability, turbine inferences in the actual wind farm and to some lacks in physical wake model.