Modeling space-time correlations of velocity fluctuations in wind farms

Laura J. Lukassen, Richard J.A.M. Stevens, Charles Meneveau, Michael Wilczek* (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

10 Citations (Scopus)
296 Downloads (Pure)

Abstract

An analytical model for the streamwise velocity space-time correlations in turbulent flows is derived and applied to the special case of velocity fluctuations in large wind farms. The model is based on the Kraichnan-Tennekes random sweeping hypothesis, capturing the decorrelation in time while including a mean wind velocity in the streamwise direction. In the resulting model, the streamwise velocity space-time correlation is expressed as a convolution of the pure space correlation with an analytical temporal decorrelation kernel. Hence, the spatiotemporal structure of velocity fluctuations in wind farms can be derived from the spatial correlations only. We then explore the applicability of the model to predict spatiotemporal correlations in turbulent flows in wind farms. Comparisons of the model with data from a large eddy simulation of flow in a large, spatially periodic wind farm are performed, where needed model parameters such as spatial and temporal integral scales and spatial correlations are determined from the large eddy simulation. Good agreement is obtained between the model and large eddy simulation data showing that spatial data may be used to model the full spatiotemporal structure of fluctuations in wind farms.

Original languageEnglish
Pages (from-to)474-487
Number of pages14
JournalWind energy
Volume21
Issue number7
Early online date12 Mar 2018
DOIs
Publication statusPublished - 1 Jul 2018

Keywords

  • Large eddy simulation
  • Power output fluctuations
  • Space-time correlations
  • Turbulent flows
  • Wind farms

Fingerprint

Dive into the research topics of 'Modeling space-time correlations of velocity fluctuations in wind farms'. Together they form a unique fingerprint.

Cite this