On the application of the Jensen wake model using a turbulence-dependent wake decay coefficient: the Sexbierum case

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Abstract

We present a methodology to process wind turbine wake simulations, which are closely related to the nature of wake observations and the processing of these to generate the so-called wake cases. The method involves averaging a large number of wake simulations over a range of wind directions and partly accounts for the uncertainty in the wind direction assuming that the same follows a Gaussian distribution. Simulations of the single and double wake measurements at the Sexbierum onshore wind farm are performed using a fast engineering wind farm wake model based on the Jensen wake model, a linearized computational fluid dynamics wake model by Fuga and a nonlinear computational fluid dynamics wake model that solves the Reynolds-averaged Navier–Stokes equations with a modified k-" turbulence model. The best agreement between models and measurements is found using the Jensen-based wake model with the suggested post-processing. We show that the wake decay coefficient of the Jensen wake model must be decreased from the commonly used onshore value of 0.075 to 0.038, when applied to the Sexbierum cases, as wake decay is related to the height, roughness and atmospheric stability and, thus, to turbulence intensity. Based on surface layer relations and assumptions between turbulence intensity and atmospheric stability, we find that at Sexbierum, the atmosphere was probably close to stable, although the stability was not observed.We support these assumptions using detailed meteorological observations from the Høvsøre site in Denmark, which is topographically similar to the Sexbierum region. © 2015 The Authors. Wind Energy published by John Wiley & Sons Ltd.
Original languageEnglish
JournalWind Energy
Volume19
Pages (from-to)763–776
Number of pages14
ISSN1095-4244
DOIs
Publication statusPublished - 2016

Bibliographical note

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Funding from the EERA DTOC project (contract FP7-ENERGY-2011/n 282797) is acknowledged. This work is carried out as part of the IEA-WakeBench research collaboration project partly funded by EUDP WakeBench (contract 64011-0308).

Keywords

  • Atmospheric stability
  • Sexbierum
  • Turbulence
  • Wake decay coefficient
  • Wake model
  • Wind direction uncertainty

Cite this

@article{9abcbbb8a86443b3b6531ed1c813dc95,
title = "On the application of the Jensen wake model using a turbulence-dependent wake decay coefficient: the Sexbierum case",
abstract = "We present a methodology to process wind turbine wake simulations, which are closely related to the nature of wake observations and the processing of these to generate the so-called wake cases. The method involves averaging a large number of wake simulations over a range of wind directions and partly accounts for the uncertainty in the wind direction assuming that the same follows a Gaussian distribution. Simulations of the single and double wake measurements at the Sexbierum onshore wind farm are performed using a fast engineering wind farm wake model based on the Jensen wake model, a linearized computational fluid dynamics wake model by Fuga and a nonlinear computational fluid dynamics wake model that solves the Reynolds-averaged Navier–Stokes equations with a modified k-{"} turbulence model. The best agreement between models and measurements is found using the Jensen-based wake model with the suggested post-processing. We show that the wake decay coefficient of the Jensen wake model must be decreased from the commonly used onshore value of 0.075 to 0.038, when applied to the Sexbierum cases, as wake decay is related to the height, roughness and atmospheric stability and, thus, to turbulence intensity. Based on surface layer relations and assumptions between turbulence intensity and atmospheric stability, we find that at Sexbierum, the atmosphere was probably close to stable, although the stability was not observed.We support these assumptions using detailed meteorological observations from the H{\o}vs{\o}re site in Denmark, which is topographically similar to the Sexbierum region. {\circledC} 2015 The Authors. Wind Energy published by John Wiley & Sons Ltd.",
keywords = "Atmospheric stability, Sexbierum, Turbulence, Wake decay coefficient, Wake model, Wind direction uncertainty",
author = "{Pena Diaz}, Alfredo and Pierre-Elouan R{\'e}thor{\'e} and {van der Laan}, Paul",
note = "This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Funding from the EERA DTOC project (contract FP7-ENERGY-2011/n 282797) is acknowledged. This work is carried out as part of the IEA-WakeBench research collaboration project partly funded by EUDP WakeBench (contract 64011-0308).",
year = "2016",
doi = "10.1002/we.1863",
language = "English",
volume = "19",
pages = "763–776",
journal = "Wind Energy",
issn = "1095-4244",
publisher = "JohnWiley & Sons Ltd.",

}

On the application of the Jensen wake model using a turbulence-dependent wake decay coefficient: the Sexbierum case. / Pena Diaz, Alfredo; Réthoré, Pierre-Elouan; van der Laan, Paul.

In: Wind Energy, Vol. 19, 2016, p. 763–776.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - On the application of the Jensen wake model using a turbulence-dependent wake decay coefficient: the Sexbierum case

AU - Pena Diaz, Alfredo

AU - Réthoré, Pierre-Elouan

AU - van der Laan, Paul

N1 - This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Funding from the EERA DTOC project (contract FP7-ENERGY-2011/n 282797) is acknowledged. This work is carried out as part of the IEA-WakeBench research collaboration project partly funded by EUDP WakeBench (contract 64011-0308).

PY - 2016

Y1 - 2016

N2 - We present a methodology to process wind turbine wake simulations, which are closely related to the nature of wake observations and the processing of these to generate the so-called wake cases. The method involves averaging a large number of wake simulations over a range of wind directions and partly accounts for the uncertainty in the wind direction assuming that the same follows a Gaussian distribution. Simulations of the single and double wake measurements at the Sexbierum onshore wind farm are performed using a fast engineering wind farm wake model based on the Jensen wake model, a linearized computational fluid dynamics wake model by Fuga and a nonlinear computational fluid dynamics wake model that solves the Reynolds-averaged Navier–Stokes equations with a modified k-" turbulence model. The best agreement between models and measurements is found using the Jensen-based wake model with the suggested post-processing. We show that the wake decay coefficient of the Jensen wake model must be decreased from the commonly used onshore value of 0.075 to 0.038, when applied to the Sexbierum cases, as wake decay is related to the height, roughness and atmospheric stability and, thus, to turbulence intensity. Based on surface layer relations and assumptions between turbulence intensity and atmospheric stability, we find that at Sexbierum, the atmosphere was probably close to stable, although the stability was not observed.We support these assumptions using detailed meteorological observations from the Høvsøre site in Denmark, which is topographically similar to the Sexbierum region. © 2015 The Authors. Wind Energy published by John Wiley & Sons Ltd.

AB - We present a methodology to process wind turbine wake simulations, which are closely related to the nature of wake observations and the processing of these to generate the so-called wake cases. The method involves averaging a large number of wake simulations over a range of wind directions and partly accounts for the uncertainty in the wind direction assuming that the same follows a Gaussian distribution. Simulations of the single and double wake measurements at the Sexbierum onshore wind farm are performed using a fast engineering wind farm wake model based on the Jensen wake model, a linearized computational fluid dynamics wake model by Fuga and a nonlinear computational fluid dynamics wake model that solves the Reynolds-averaged Navier–Stokes equations with a modified k-" turbulence model. The best agreement between models and measurements is found using the Jensen-based wake model with the suggested post-processing. We show that the wake decay coefficient of the Jensen wake model must be decreased from the commonly used onshore value of 0.075 to 0.038, when applied to the Sexbierum cases, as wake decay is related to the height, roughness and atmospheric stability and, thus, to turbulence intensity. Based on surface layer relations and assumptions between turbulence intensity and atmospheric stability, we find that at Sexbierum, the atmosphere was probably close to stable, although the stability was not observed.We support these assumptions using detailed meteorological observations from the Høvsøre site in Denmark, which is topographically similar to the Sexbierum region. © 2015 The Authors. Wind Energy published by John Wiley & Sons Ltd.

KW - Atmospheric stability

KW - Sexbierum

KW - Turbulence

KW - Wake decay coefficient

KW - Wake model

KW - Wind direction uncertainty

U2 - 10.1002/we.1863

DO - 10.1002/we.1863

M3 - Journal article

VL - 19

SP - 763

EP - 776

JO - Wind Energy

JF - Wind Energy

SN - 1095-4244

ER -