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On vortex rings around vortices: an optimal mechanism

Antkowiak, Arnaud and Brancher, Pierre On vortex rings around vortices: an optimal mechanism. (2007) Journal of Fluid Mechanics, 578. 295-304. ISSN 0022-1120

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Official URL: http://dx.doi.org/10.1017/S0022112007005198

Abstract

Stable columnar vortices subject to hydrodynamic noise (\eg turbulence) present some recurrent behaviours like the systematic development of vortex rings at the periphery of the vortex core. This phenomenon still lacks a comprehensive explanation, partly because it is not associated to an instability \textit{stricto sensu}. The aim of the present paper is to identify the physical mechanism triggering this intrinsic feature of vortices using an optimal perturbation analysis as a tool of investigation. We found that the generation of vortex rings is linked to the intense and rapid amplification of specific disturbances in the form of azimuthal velocity streaks that eventually evolve into azimuthal vorticity rolls generated by the rotational part of the local Coriolis force. This evolution thus appears to follow a scenario opposite to the classical lift-up view, where rolls give rise to streaks.

Item Type:Article
Additional Information:Thanks to Cambridge University Press editor.The original PDF of the article can be found athttps://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/on-vortex-rings-around-vortices-an-optimal-mechanism/89856CE837C15887D37E57D0FC8733D7
HAL Id:hal-01727319
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
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Deposited By: Pierre BRANCHER
Deposited On:09 Mar 2018 09:12

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