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Study of the effect of the presence of downstream turbines on upstream ones and use of a controller in CFD wind turbine simulation models
KTH, School of Engineering Sciences (SCI), Mechanics.
KTH, School of Engineering Sciences (SCI), Mechanics.
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2012 (English)Conference paper, Published paper (Other academic)
Place, publisher, year, edition, pages
2012.
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:kth:diva-109521OAI: oai:DiVA.org:kth-109521DiVA: diva2:583079
Conference
The Science of Making Torque from Wind
Funder
Swedish e‐Science Research CenterStandUp
Note

QC 20130111

Available from: 2013-01-07 Created: 2013-01-07 Last updated: 2013-04-18Bibliographically approved
In thesis
1. Numerical computations of wind turbine wakes and wake interaction: Optimization and control
Open this publication in new window or tab >>Numerical computations of wind turbine wakes and wake interaction: Optimization and control
2012 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

In the present thesis the wake flow behind wind turbines is analyzed numerically using large-eddy simulations. The wind turbine rotors are modeled by using either the actuator disc method or the actuator line method in which the blades are represented by body forces computed with airfoil data. Using these models, the boundary layers of the turbine blades are not resolved and most of the computational power is preserved to simulate the wake flow. The actuator disc method is used for the wake interaction studies of the Lillgrund wind farm. In this study the power production is simulated for two different wind directions and compared to measurements. A grid sensitivity study and a turbulence intensity study are also performed. As a last step the front row turbines are derated in an attempt to increase the total production of the farm. The results show that it is important to impose atmospheric conditions at the inlet in the simulations, otherwise production will be unrealistically low for some turbines in the farm. The agreement between the simulated and measured power is very good. The study based on derating the front row turbines does not show any positive increase on the farm production. The actuator line method is used for near wake analysis of the MEXICO rotor. In this study the near wake is simulated for five different flow cases and compared with particle image velocimetry (PIV) measurements. The analysis is performed by comparing size and circulation of the tip vortices, the radial and streamwise velocity distributions, the spatial expansion of the wake and the axial induction factor. The simulations and measurements generally are in agreement. In some cases, however, the measurements are affected by tunnel effects which are not captured in the simulations. In connection to the actuator disc method a power control strategy for operating conditions below rated power is implemented and tested. The strategy is first validated using an in-house developed blade element momentum code and then is implemented in the actuator disc method used in the EllipSys3D code. The initial tests show that the strategy responds as expected when changing the moment of inertia of the rotor and when varying the inlet conditions. Results from the implementation of the strategy in the actuator disc method in EllipSys3D show that the turbine adapts to the conditions it is operating in by changing its rotational velocity and power output when the inlet conditions are varied.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. vi, 56 p.
Series
Trita-MEK, ISSN 0348-467X ; 2012:18
Keyword
Actuator disc method, Actuator line method, Blade element momentum method, Wind turbine wake, Wake interaction, CFD, LES, EllipSys3D
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-109522 (URN)978-91-7501-624-5 (ISBN)
Presentation
2013-01-25, D33, Lindstedtsvägen 5, KTH, Stockholm, 10:15 (English)
Opponent
Supervisors
Note

QC 20130111

Available from: 2013-01-11 Created: 2013-01-07 Last updated: 2013-01-11Bibliographically approved

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CiteExportLink to record
Permanent link

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Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
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