Comparison of wind farm large eddy simulations using actuator disk and actuator line models with wind tunnel experiments

Richard J.A.M Stevens,Luis A Martínez-Tossas,Charles Meneveau

doi:10.1016/j.renene.2017.08.072

Richard J.A.M Stevens, Luis A Martínez-Tossas + Show 1 more

Open Access

https://doi.org/10.1016/j.renene.2017.08.072

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Journal: Renewable Energy	Publication Date: Aug 29, 2017
Citations: 170	License type: cc-by

Affiliation: Johns Hopkins University, University of Twente

Abstract

We compare wind farm large eddy simulations with the EPFL wind tunnel measurement by Chamorro and Porté-Agel (Bound-Lay. Meteorol. 136, 515 (2010) and Energies 4, 1916 (2011)). We find that the near turbine wake, up to 3 turbine diameters downstream, of a single turbine is captured better with the actuator line method than using the actuator disk method. Further downstream the results obtained with both models agrees very well with the experimental data, confirming findings from previous studies. For large aligned wind farms we find that the actuator disk model predicts the wake profiles behind turbines on the second and subsequent rows more accurately than the wake profile behind the first turbine row. The reason is that the wake layer profile that is created at hub height in very large wind farms is closer to the assumptions made in the actuator disk model than the logarithmic profile found in the inflow conditions. In addition, we show that, even in relatively coarse resolution simulations, adding the effect of the turbine nacelle and tower leads to a significant improvement in the prediction of the near wake features at 1 and 2 diameters downstream.

Highlights

Large eddy simulation (LES) has become a prominent tool for performing high-fidelity numerical simulations of wind farm flows [1,2,3]
In this paper we compare the performance of the actuator disk model (ADM) and the actuator line model (ALM) on relatively coarse grids, while we consider the influence of modeling the nacelle and tower
In agreement with literature results [3,19,22,27,28,29,45] we find that starting at 3 turbine diameters downstream the velocity profile obtained using the ADM and ALM match the results obtained from the experiments closely

Summary

Introduction

Large eddy simulation (LES) has become a prominent tool for performing high-fidelity numerical simulations of wind farm flows [1,2,3]. When performing wind farm simulations with many turbines, fine grid resolutions are often not affordable. We mention the blind tests workshops by Krogstad et al [4,5], and Pierella et al [6] in which the wake evolution behind single or two wind turbines was compared with different simulation and modeling approaches. For an overview of different wind turbine modeling approaches we refer to the reviews by Sanderse et al [12] and Sørensen [1]. Comparisons of wind farm LES with field measurement data can, for example, be found in Refs. Different wind farm modeling approaches are reviewed in Ref. Different wind farm modeling approaches are reviewed in Ref. [19]

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