Characterization of long time fluctuations of forces exerted on an oscillating circular cylinder at KC = 10 - ENSTA Paris - École nationale supérieure de techniques avancées Paris Accéder directement au contenu
Article Dans Une Revue Journal of Fluids and Structures Année : 2011

Characterization of long time fluctuations of forces exerted on an oscillating circular cylinder at KC = 10

Résumé

Flow dynamics, in-line and transverse forces exerted on an oscillating circular cylinder in a fluid initially at rest are studied by numerical resolution of the two-dimensional Navier–Stokes equations. The Keulegan–Carpenter number is held constant at KC = 10 and Re is increased from 40 to 500. For the different flow regimes, links between flow spatio-temporal symmetries and force histories are established. Besides simulations of long duration show that in two ranges of Re, forces exhibit low frequency fluctuations compared to the cylinder oscillation frequency. Such observations have been only mentioned in the literature and are more deeply examined here. In both ranges, force fluctuations correspond to oscillations of the front and rear stagnation points on the cylinder surface. However, they occur in flow regimes whose basic patterns (V-shaped mode or diagonal mode) have different symmetry features, inducing two distinct behaviors. For 80 < Re < 100, fluctuations are related to a spectral broadening of the harmonics and to a permutation between three vortex patterns (V-shaped, transverse and oblique modes). In the second range 150 < Re < 280, amplitude fluctuations are correlated to the appearance of low frequency peaks interacting with harmonics of the cylinder frequency. Fluctuations are then a combination of a wavy fluctuation and an amplitude modulation. The carrier frequency corresponding to the wavy fluctuation depends on Re and is related to a fluid characteristic time; the modulation frequency is independent of Re and equal to 1/4 of the cylinder oscillation frequency.
Fichier principal
Vignette du fichier
MDDB.pdf (4.28 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01289913 , version 1 (24-11-2017)

Identifiants

Citer

Marion Duclercq, Daniel Broc, Olivier Cadot. Characterization of long time fluctuations of forces exerted on an oscillating circular cylinder at KC = 10. Journal of Fluids and Structures, 2011, 27 (4), pp.596-610. ⟨10.1016/j.jfluidstructs.2011.01.004⟩. ⟨hal-01289913⟩
43 Consultations
160 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More