000014773 001__ 14773
000014773 005__ 20161115100201.0
000014773 04107 $$aeng
000014773 046__ $$k2016-08-21
000014773 100__ $$aLe Dizes, Stéphane
000014773 24500 $$aCurvature and elliptic instabilities in helical vortices (INVITED)

000014773 24630 $$n24.$$p24th International Congress of Theoretical and Applied Mechanics - Book of Papers
000014773 260__ $$bInternational Union of Theoretical and Applied Mechanics, 2016
000014773 506__ $$arestricted
000014773 520__ $$2eng$$aShort-wavelength instabilities of helical vortices are analysed using a combined theoretical and numerical approach. The helical vortices are described using an asymptotic approach in the limit of small core size (compared to the pitch and the radius of the helix). Both the curvature instability induced by the local vortex curvature and the elliptic instability induced by the strain field deformation are considered for a vortex with Gaussian axial vorticity and axial velocity (Batchelor vortex). Theoretical predictions are obtained for the growth rate of each instability and used to analyse the competition between both instabilities. We show the crucial role of the axial flow component of the Batchelor vortex in the selection of the dominant instability. For weak axial flow, the elliptic instability is found to dominate the curvature instability, whereas it is the opposite when the axial flow is no longer negligible. The results are compared to recent experimental observations.

000014773 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000014773 653__ $$a

000014773 7112_ $$a24th International Congress of Theoretical and Applied Mechanics$$cMontreal (CA)$$d2016-08-21 / 2016-08-26$$gICTAM2016
000014773 720__ $$aLe Dizes, Stéphane
000014773 8560_ $$ffischerc@itam.cas.cz
000014773 8564_ $$s37072$$uhttps://invenio.itam.cas.cz/record/14773/files/TS.FM15-4.02.pdf$$yOriginal version of the author's contribution as presented on CD,  page 1538, code TS.FM15-4.02
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000014773 962__ $$r13812
000014773 980__ $$aPAPER