Journal of Fluid Mechanics



Bénard-von Kármán instability: transient and forced regimes


M.  Provansal a1, C.  Mathis a2 and L.  Boyer a3
a1 Laboratoire de Recherche en Combustion, U.A 1117 du CNRS, Université de Provence, Centre de Saint-Jérôme, 13397 Marseille cedex 13, France
a2 Laboratoire de Physique de la Matière Condensée, U.A 190 du CNRS, Université de Nice, Parc Valrose, 06034 Nice, France
a3 Laboratoire de Recherche en Combustion, U.A 1117 du CNRS, Université de Provence, Centre de Saint-Jérôme, 13397 Marseille cedex 13, France

Article author query
provansal m   [Google Scholar] 
mathis c   [Google Scholar] 
boyer l   [Google Scholar] 
 

Abstract

The wake of a circular cylinder is investigated near the oscillation threshold by means of a laser probe. Above the threshold the transient regime is studied and described by a Stuart-Landau law (already found to be relevant in explaining free-oscillating regimes). Below the critical point, impulse and resonant regimes are examined, so the coefficients of the Stuart-Landau equation are determined.

Moreover, in the supercritical regime, the behaviour of the (externally forced) oscillating system is described, varying parameters such as threshold deviation, forcing frequency and amplitude. The different zones of entrainment and desynchronization are given for simple or harmonic frequency.

(Published Online April 21 2006)
(Received January 2 1986)
(Revised February 7 1987)



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