Development of a Computational System to Improve Wind Farm Layout, Part I: Model Validation and Near Wake Analysis

Abstract

The first part of this work describes the validation of a wind turbine farm Computational Fluid Dynamics (CFD) simulation using literature velocity wake data from the MEXICO (Model Experiments in Controlled Conditions) experiment. The work is intended to establish a computational framework from which to investigate wind farm layout, seeking to validate the simulation and identify parameters influencing the wake. A CFD model was designed to mimic the MEXICO rotor experimental conditions and simulate new operating conditions with regards to tip speed ratio and pitch angle. The validation showed that the computational results qualitatively agree with the experimental data. Considering the designed tip speed ratio (TSR) of 6.6, the deficit of velocity in the wake remains at rate of approximately 15% of the free-stream velocity per rotor diameter regardless of the free-stream velocity applied. Moreover, analysis of a radial traverse right behind the rotor showed an increase of 20% in the velocity deficit as the TSR varied from TSR = 6 to TSR = 10, corresponding to an increase ratio of approximately 5% m·s−1 per dimensionless unit of TSR. We conclude that the near wake characteristics of a wind turbine are strongly influenced by the TSR and the pitch angle.

Development of a Computational System to Improve Wind Farm Layout, Part II: Wind Turbine Wakes Interaction

“…The wind turbine modeled in this work was adapted from the previously validated wind turbine CFD model from part I [56], the MEXICO (Model Experiments in Controlled Conditions) rotor (4.5 m diameter) [57] tested in wind tunnel. The wind turbine blade geometry (MEXICO rotor) including twist angle was built using SolidWorks, and then imported to the ANSYS Design Modeler to build the other turbine components (tower, hub) and the physical domain ( Figure 1).…”

“…The wake was simulated with a domain extending 13 diameters downstream of the rotor. The CFD model of this study was adapted from part I of this research [56], which is a validation and near wake analysis of the MEXICO rotor. In part I [56], the wind tunnel inlet is located 7 m upstream of the rotor.…”

“…The CFD model of this study was adapted from part I of this research [56], which is a validation and near wake analysis of the MEXICO rotor. In part I [56], the wind tunnel inlet is located 7 m upstream of the rotor. In the current study, the same distance was adopted as the length upstream of the wind turbine.…”

“…The loading on the blades is represented using the rotating central disc from Figure 1b, but careful work has been taken to correctly represent these forces. The model validation process can be found in the first part of this research [56], including blade loading, pressure coefficient on the blades, and near wake velocity flow field. Additionally, more details about the numerical modeling process can be found in part I [56].…”

Reproduction of Local Strong Wind Area Induced in the Downstream of Small-Scale Terrain by Computational Fluid Dynamic (CFD) Approach

“…In Japan, wind power generation is also the leading source of renewable energy; the further prevalence of wind power generation throughout the world will surely contribute to the overcoming of global warming (green innovation). One of the technical problems to be solved in the future in the field of wind power generation is to correctly understand the local wind conditions which are generated around wind turbines and establish a computational wind prospecting technology with higher accuracy than before that can be applied to the survey before the introduction of wind turbines [1][2][3][4][5][6][7][8][9][10][11]. e author's group narrowed the scales down from several m to several km and is developing a computational wind prospecting model that can reproduce local wind conditions with high accuracy (RIAM-COMPACT) [12][13][14][15][16][17][18][19][20][21].…”