Increase in the annual energy production due to a retrofit of vortex generators on blades

Witold Robert Skrzypinski, Mac Gaunaa, Christian Bak, Birgit Junker, Niels Bruhn Brønnum, Emil Krog Kruse

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The aim of the current work was to analyze the effect of retrofitting vortex generators (VGs) on the blades of a constant RPM, pitch‐regulated, megawatt‐sized turbine suffering from surface roughness. Engineering modelling and experimental work were utilized, indicating that the degradation of energy production may be mitigated by the VGs. The modelling results indicated that the optimal configuration of VGs to maximize the annual energy production (AEP) depends on the degree of severity of surface roughness. Depending on blade surface condition and turbine characteristics, installation of VGs on an incorrect blade span or installation of too large VGs too far out on the blade may cause loss in the AEP. Therefore, engineering modelling is necessary before VGs may be retrofitted on a specific turbine. The modelling results indicated that the worse blade surface, the more gain may be obtained from the VGs. The work included a full‐scale experimental validation of the present engineering model, lasting 27 months and comprising six turbines where VGs were mounted on three, each with a neighboring turbine as a reference. The turbines were analyzed in pairs, and the influence of the VGs was judged upon the relative difference in energy production before and after the installation. The reason was to limit measurement uncertainty. The results showed that all three turbines increased their energy production after the installation. Results from the three pairs showed an average increase in the energy production of 3.3%, being satisfactorily close to the average 2.8% predicted by the present engineering tool.
Original languageEnglish
Article number2446
JournalWind Energy
Number of pages10
ISSN1095-4244
DOIs
Publication statusAccepted/In press - 2019

Keywords

  • Aerodynamics
  • Blade surface roughness
  • Engineering modelling
  • Erosion
  • Full‐scale experiment
  • Leading edge roughness
  • Sidebyside experiment
  • Vortex generator

Cite this

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title = "Increase in the annual energy production due to a retrofit of vortex generators on blades",
abstract = "The aim of the current work was to analyze the effect of retrofitting vortex generators (VGs) on the blades of a constant RPM, pitch‐regulated, megawatt‐sized turbine suffering from surface roughness. Engineering modelling and experimental work were utilized, indicating that the degradation of energy production may be mitigated by the VGs. The modelling results indicated that the optimal configuration of VGs to maximize the annual energy production (AEP) depends on the degree of severity of surface roughness. Depending on blade surface condition and turbine characteristics, installation of VGs on an incorrect blade span or installation of too large VGs too far out on the blade may cause loss in the AEP. Therefore, engineering modelling is necessary before VGs may be retrofitted on a specific turbine. The modelling results indicated that the worse blade surface, the more gain may be obtained from the VGs. The work included a full‐scale experimental validation of the present engineering model, lasting 27 months and comprising six turbines where VGs were mounted on three, each with a neighboring turbine as a reference. The turbines were analyzed in pairs, and the influence of the VGs was judged upon the relative difference in energy production before and after the installation. The reason was to limit measurement uncertainty. The results showed that all three turbines increased their energy production after the installation. Results from the three pairs showed an average increase in the energy production of 3.3{\%}, being satisfactorily close to the average 2.8{\%} predicted by the present engineering tool.",
keywords = "Aerodynamics, Blade surface roughness, Engineering modelling, Erosion, Full‐scale experiment, Leading edge roughness, Sidebyside experiment, Vortex generator",
author = "Skrzypinski, {Witold Robert} and Mac Gaunaa and Christian Bak and Birgit Junker and Br{\o}nnum, {Niels Bruhn} and Kruse, {Emil Krog}",
year = "2019",
doi = "10.1002/we.2446",
language = "English",
journal = "Wind Energy",
issn = "1095-4244",
publisher = "JohnWiley & Sons Ltd.",

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Increase in the annual energy production due to a retrofit of vortex generators on blades. / Skrzypinski, Witold Robert; Gaunaa, Mac; Bak, Christian; Junker, Birgit ; Brønnum, Niels Bruhn ; Kruse, Emil Krog.

In: Wind Energy, 2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Increase in the annual energy production due to a retrofit of vortex generators on blades

AU - Skrzypinski, Witold Robert

AU - Gaunaa, Mac

AU - Bak, Christian

AU - Junker, Birgit

AU - Brønnum, Niels Bruhn

AU - Kruse, Emil Krog

PY - 2019

Y1 - 2019

N2 - The aim of the current work was to analyze the effect of retrofitting vortex generators (VGs) on the blades of a constant RPM, pitch‐regulated, megawatt‐sized turbine suffering from surface roughness. Engineering modelling and experimental work were utilized, indicating that the degradation of energy production may be mitigated by the VGs. The modelling results indicated that the optimal configuration of VGs to maximize the annual energy production (AEP) depends on the degree of severity of surface roughness. Depending on blade surface condition and turbine characteristics, installation of VGs on an incorrect blade span or installation of too large VGs too far out on the blade may cause loss in the AEP. Therefore, engineering modelling is necessary before VGs may be retrofitted on a specific turbine. The modelling results indicated that the worse blade surface, the more gain may be obtained from the VGs. The work included a full‐scale experimental validation of the present engineering model, lasting 27 months and comprising six turbines where VGs were mounted on three, each with a neighboring turbine as a reference. The turbines were analyzed in pairs, and the influence of the VGs was judged upon the relative difference in energy production before and after the installation. The reason was to limit measurement uncertainty. The results showed that all three turbines increased their energy production after the installation. Results from the three pairs showed an average increase in the energy production of 3.3%, being satisfactorily close to the average 2.8% predicted by the present engineering tool.

AB - The aim of the current work was to analyze the effect of retrofitting vortex generators (VGs) on the blades of a constant RPM, pitch‐regulated, megawatt‐sized turbine suffering from surface roughness. Engineering modelling and experimental work were utilized, indicating that the degradation of energy production may be mitigated by the VGs. The modelling results indicated that the optimal configuration of VGs to maximize the annual energy production (AEP) depends on the degree of severity of surface roughness. Depending on blade surface condition and turbine characteristics, installation of VGs on an incorrect blade span or installation of too large VGs too far out on the blade may cause loss in the AEP. Therefore, engineering modelling is necessary before VGs may be retrofitted on a specific turbine. The modelling results indicated that the worse blade surface, the more gain may be obtained from the VGs. The work included a full‐scale experimental validation of the present engineering model, lasting 27 months and comprising six turbines where VGs were mounted on three, each with a neighboring turbine as a reference. The turbines were analyzed in pairs, and the influence of the VGs was judged upon the relative difference in energy production before and after the installation. The reason was to limit measurement uncertainty. The results showed that all three turbines increased their energy production after the installation. Results from the three pairs showed an average increase in the energy production of 3.3%, being satisfactorily close to the average 2.8% predicted by the present engineering tool.

KW - Aerodynamics

KW - Blade surface roughness

KW - Engineering modelling

KW - Erosion

KW - Full‐scale experiment

KW - Leading edge roughness

KW - Sidebyside experiment

KW - Vortex generator

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DO - 10.1002/we.2446

M3 - Journal article

JO - Wind Energy

JF - Wind Energy

SN - 1095-4244

M1 - 2446

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