Non-conventional vortex generators calculated with CFD

Méndez, Beatriz; Gutierrez, Ronald A.

doi:10.1088/1742-6596/1037/2/022029

Cited by 3 publications

(2 citation statements)

References 2 publications

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“…The result also agreed with the results obtained by Yao et al [15] and Fernandez-Gamiz et al [16]. The work of Mendez and Gutierrez-Amo [17] provided a CFD study of two non-conventional VGs geometries based on a constant airfoil cross-section on a flat plate compared with a Rectangular VG. A reduction of the local drag penalty using VGs with a cross-section based on airfoils was shown on a negligible pressure gradient flat plate.…”

Section: Introductionsupporting

confidence: 89%

Computational Modelling of Three Different Sub-Boundary Layer Vortex Generators on a Flat Plate

et al. 2018

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Flow separation is the source of several problems in a wind turbine including load fluctuations, lift losses, and vibrations. Vortex generators (VGs) are passive flow control devices used to delay flow separation, but their implementation may produce overload drag at the blade section where they are placed. In the current work, a computational model of different geometries of vortex generators placed on a flat plate has been carried out throughout fully meshed computational simulations using Reynolds Averaged Navier-Stokes (RANS) equations performed at a Reynolds number of R e θ = 2600 based on local boundary layer (BL) momentum thickness θ = 2.4 mm. A flow characterization of the wake behind the vortex generator has been done with the aim of evaluating the performance of three vortex generator geometries, namely Rectangular VG, Triangular VG, and Symmetrical VG NACA0012. The location of the primary vortex has been evaluated by the vertical and lateral trajectories and it has been found that for all analyzed VG geometries the primary vortex is developed below the boundary layer thickness δ = 20 mm for a similar vorticity level ( w x m a x ). Two innovative parameters have been developed in the present work for evaluating the vortex size and the vortex strength: Half-Life Surface S 05 and Mean Positive Circulation Γ 05 + . As a result, an assessment of the VG performance has been carried out by all analyzed parameters and the symmetrical vortex generator NACA0012 has provided good efficiency in energy transfer compared with the Rectangular VG.

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Section: Introductionsupporting

confidence: 89%

Computational Modelling of Three Different Sub-Boundary Layer Vortex Generators on a Flat Plate

et al. 2018

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“…Vortex generators (VGs), widely used in the aircraft industry, eg, to increase the maximum takeoff weight of airplanes, have also occupied many wind turbine blades over the last decade. However, even though numerous investigations have been carried out, including studies of various alternative aerodynamic shapes of VGs, further studies are required in order to learn to what extent the VGs benefit specific turbines and where exactly they need to be installed on the blades in order to maximize energy production. In that, many factors come into play, eg, condition of blade surface material, its rate of erosion, geometrical accuracy of blade sections, or operational conditions.…”

Section: Introductionmentioning

confidence: 99%

Increase in the annual energy production due to a retrofit of vortex generators on blades

et al. 2019

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The aim of the current work was to analyze the effect of retrofitting vortex generators (VGs) on the blades of a constant RPM, pitch-regulated, megawatt-sized turbine suffering from surface roughness. Engineering modelling and experimental work were utilized, indicating that the degradation of energy production may be mitigated by the VGs. The modelling results indicated that the optimal configuration of VGs to maximize the annual energy production (AEP) depends on the degree of severity of surface roughness. Depending on blade surface condition and turbine characteristics, installation of VGs on an incorrect blade span or installation of too large VGs too far out on the blade may cause loss in the AEP. Therefore, engineering modelling is necessary before VGs may be retrofitted on a specific turbine. The modelling results indicated that the worse blade surface, the more gain may be obtained from the VGs.The work included a full-scale experimental validation of the present engineering model, lasting 27 months and comprising six turbines where VGs were mounted on three, each with a neighboring turbine as a reference. The turbines were analyzed in pairs, and the influence of the VGs was judged upon the relative difference in energy production before and after the installation. The reason was to limit measurement uncertainty. The results showed that all three turbines increased their energy production after the installation. Results from the three pairs showed an average increase in the energy production of 3.3%, being satisfactorily close to the average 2.8% predicted by the present engineering tool.

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