Airfoil Thickness Effects on Dynamic Stall Onset

dc.contributor.author Sharma, Anupam
dc.contributor.author Visbal, Miguel
dc.contributor.author Sharma, Anupam
dc.contributor.department Aerospace Engineering
dc.date 2018-10-19T22:10:27.000
dc.date.accessioned 2020-06-29T22:45:01Z
dc.date.available 2020-06-29T22:45:01Z
dc.date.embargo 2018-10-18
dc.date.issued 2017-01-01
dc.description.abstract <p>Large eddy simulations are used to investigate the effects of airfoil geometry, particularly thickness, on inception of dynamic stall. The investigation is performed for three airfoils from the NACA family at Re<sub>c</sub> = 2 x 10<sup>5</sup>. Three symmetric airfoils are studied with thickness-to-chord ratios of 9%, 12%, and 15%. A constant-rate pitch-up motion about the airfoil quarter-chord point is used to study dynamic stall. A static simulation is first carried out with each airfoil set at alpha = 4 degrees. Results of the static simulations are compared with XFOIL predictions as a sanity check. Good code-to-code agreement is observed for aerodynamic pressure- and skin friction coefficient distributions. A ramp function is used to smoothly increase the pitch rate from zero to the desired value and then held fixed. Dynamic simulations are carried out until the angle of attack goes past the lift stall point. Unsteady aerodynamic loads are compared with the corresponding static values. In all cases, dynamic stall onset occurs immediately following the bursting of the laminar separation bubble. However, investigation of the reverse flow region on the suction surface shows tremendous differences between the different airfoils, with the thickest airfoil showing a very large reverse flow region. These observations suggests that the mechanism of stall onset can change from 'LSB burst' to trailing edge separation as airfoil thickness is further increased.</p>
dc.description.comments <p>This proceeding is published as Sharma, Anupam and Miguel R. Visbal. "Airfoil Thickness Effects on Dynamic Stall Onset", 23rd AIAA Computational Fluid Dynamics Conference, AIAA AVIATION Forum, (AIAA 2017-3957). (2017). DOI: <a href="https://dx.doi.org/10.2514/6.2017-3957" target="_blank">10.2514/6.2017-3957</a>.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/aere_conf/39/
dc.identifier.articleid 1038
dc.identifier.contextkey 13113416
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath aere_conf/39
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/1917
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/aere_conf/39/2017_SharmaAnupam_AirfoilThickness.pdf|||Fri Jan 14 23:55:12 UTC 2022
dc.source.uri 10.2514/6.2017-3957
dc.subject.disciplines Aerodynamics and Fluid Mechanics
dc.subject.disciplines Aerospace Engineering
dc.subject.disciplines Structures and Materials
dc.title Airfoil Thickness Effects on Dynamic Stall Onset
dc.type article
dc.type.genre conference
dspace.entity.type Publication
relation.isAuthorOfPublication 9797e35d-08ee-41c7-8982-c83e6db2ed8e
relation.isOrgUnitOfPublication 047b23ca-7bd7-4194-b084-c4181d33d95d
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