How does turbulence change approaching a rotor?
For load calculations on wind turbines it is usually assumed that the turbulence approaching the rotor does not change its statistics as it goes through the induction zone. We investigate this assumption using a nacelle-mounted forward-looking pulsed lidar that measures low-frequency wind fluctu...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-05-01
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| Series: | Wind Energy Science |
| Online Access: | https://www.wind-energ-sci.net/3/293/2018/wes-3-293-2018.pdf |
| _version_ | 1831735904462438400 |
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| author | J. Mann A. Peña N. Troldborg S. J. Andersen |
| author_facet | J. Mann A. Peña N. Troldborg S. J. Andersen |
| author_sort | J. Mann |
| collection | DOAJ |
| description | For load calculations on wind turbines it is usually assumed that the
turbulence approaching the rotor does not change its statistics as it goes
through the induction zone. We investigate this assumption using a
nacelle-mounted forward-looking pulsed lidar that measures low-frequency wind
fluctuations simultaneously at distances between 0.5 and 3 rotor diameters
upstream. The measurements show that below rated wind speed the low-frequency
wind variance is reduced by up to 10 % at 0.5 rotor diameters upstream and
above rated enhanced by up to 20 %. A quasi-steady model that takes into
account the change in thrust coefficient with wind speed explains these
variations partly. Large eddy simulations of turbulence approaching an
actuator disk model of a rotor support the finding that the slope of the
thrust curve influences the low-frequency fluctuations. |
| first_indexed | 2024-12-21T12:35:17Z |
| format | Article |
| id | doaj.art-448e73a98fe1471a9ff899edadfbad7d |
| institution | Directory Open Access Journal |
| issn | 2366-7443 2366-7451 |
| language | English |
| last_indexed | 2024-12-21T12:35:17Z |
| publishDate | 2018-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Wind Energy Science |
| spelling | doaj.art-448e73a98fe1471a9ff899edadfbad7d2022-12-21T19:03:55ZengCopernicus PublicationsWind Energy Science2366-74432366-74512018-05-01329330010.5194/wes-3-293-2018How does turbulence change approaching a rotor?J. Mann0A. Peña1N. Troldborg2S. J. Andersen3DTU Wind Energy, Technical University of Denmark, Roskilde, DenmarkDTU Wind Energy, Technical University of Denmark, Roskilde, DenmarkDTU Wind Energy, Technical University of Denmark, Roskilde, DenmarkDTU Wind Energy, Technical University of Denmark, Roskilde, DenmarkFor load calculations on wind turbines it is usually assumed that the turbulence approaching the rotor does not change its statistics as it goes through the induction zone. We investigate this assumption using a nacelle-mounted forward-looking pulsed lidar that measures low-frequency wind fluctuations simultaneously at distances between 0.5 and 3 rotor diameters upstream. The measurements show that below rated wind speed the low-frequency wind variance is reduced by up to 10 % at 0.5 rotor diameters upstream and above rated enhanced by up to 20 %. A quasi-steady model that takes into account the change in thrust coefficient with wind speed explains these variations partly. Large eddy simulations of turbulence approaching an actuator disk model of a rotor support the finding that the slope of the thrust curve influences the low-frequency fluctuations.https://www.wind-energ-sci.net/3/293/2018/wes-3-293-2018.pdf |
| spellingShingle | J. Mann A. Peña N. Troldborg S. J. Andersen How does turbulence change approaching a rotor? Wind Energy Science |
| title | How does turbulence change approaching a rotor? |
| title_full | How does turbulence change approaching a rotor? |
| title_fullStr | How does turbulence change approaching a rotor? |
| title_full_unstemmed | How does turbulence change approaching a rotor? |
| title_short | How does turbulence change approaching a rotor? |
| title_sort | how does turbulence change approaching a rotor |
| url | https://www.wind-energ-sci.net/3/293/2018/wes-3-293-2018.pdf |
| work_keys_str_mv | AT jmann howdoesturbulencechangeapproachingarotor AT apena howdoesturbulencechangeapproachingarotor AT ntroldborg howdoesturbulencechangeapproachingarotor AT sjandersen howdoesturbulencechangeapproachingarotor |