A simplified vortex model of propeller and wind-turbine wakes
2013 (English)In: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 725, 91-116 p.Article in journal (Refereed) Published
A new vortex model of inviscid propeller and wind-turbine wakes is proposed based on an asymptotic expansion of the Biot-Savart induction law to account for the finite vortex core size. The circulation along the blade is assumed to be constant from the blade root to the tip approximating a turbine with maximum power production for given operating conditions. The model iteratively calculates the tip-vortex path, allowing the wake to expand/contract freely, and is afterward able to evaluate the velocity field in the whole domain. The 'roller-bearing analogy', proposed by Okulov and Sorensen (J. Fluid Mech., vol. 649, 2010, pp. 497-508), is used to determine the vortex core size. A comparison of the main outcomes of the present model with the general momentum theory is performed in terms of the operating parameters (namely the number of blades, the tip-speed ratio, the blade circulation and the vortex core size), demonstrating good agreement between the two. Furthermore, experimental data have been compared with the model outputs to validate the model under real operating conditions.
Place, publisher, year, edition, pages
2013. Vol. 725, 91-116 p.
vortex flows, vortex dynamics, wakes/jets
IdentifiersURN: urn:nbn:se:kth:diva-124449DOI: 10.1017/jfm.2013.182ISI: 000319511200005ScopusID: 2-s2.0-84878188934OAI: oai:DiVA.org:kth-124449DiVA: diva2:636491
QC 201507202013-07-102013-07-052015-07-20Bibliographically approved