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Muro, Blas
Publications (1 of 1) Show all publications
Ebenhoch, R., Muro, B., Dahlberg, J.-Å., Berkesten Hägglund, P. & Segalini, A. (2017). A linearized numerical model of wind-farm flows. Wind Energy, 20(5), 859-875
Open this publication in new window or tab >>A linearized numerical model of wind-farm flows
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2017 (English)In: Wind Energy, ISSN 1095-4244, E-ISSN 1099-1824, Vol. 20, no 5, p. 859-875Article in journal (Refereed) Published
Abstract [en]

A fast and reasonably accurate numerical three-dimensional wake model able to predict the flow behaviour of a wind farm over a flat terrain has been developed. The model is based on the boundary-layer approximation of the Navier-Stokes equations, linearized around the incoming atmospheric boundary layer, with the assumption that the wind turbines provide a small perturbation to the velocity field. The linearization of the actuator-disc theory brought additional insights that could be used to understand the behaviour, as well as the limitations, of a flow model based on linear methods: for instance, it is shown that an adjustment of the turbine's thrust coefficient is necessary in order to obtain the same wake velocity field provided by the actuator disc theory within the used linear framework. The model is here validated against two independent wind-tunnel campaigns with a small and a large wind farm aimed at the characterization of the flow above and upstream of the farms, respectively. The developed model is, in contrary to current engineering wake models, able to account for effects occurring in the upstream flow region, thereby including more physical mechanisms than other simplified approaches. The conducted simulations (in agreement with the measurement results) show that the presence of a wind farm affects the approaching flow far more upstream than generally expected and definitely beyond the current industrial standards. Despite the model assumptions, several velocity statistics above wind farms have been properly estimated providing an insight into the transfer of momentum inside the turbine rows.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
Keywords
blockage effect, numerical wake model, linearized RANs, internal boundary layer, dispersive stresses
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-208244 (URN)10.1002/we.2067 (DOI)000398845300007 ()2-s2.0-85000909957 (Scopus ID)
Funder
StandUp for Wind
Note

QC 20170627

Available from: 2017-06-27 Created: 2017-06-27 Last updated: 2017-06-27Bibliographically approved
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