Deformation of a flexible polymer in a random flow with long correlation time

Stefano Musacchio (1) , Dario Vincenzi (1)

1 JAD - Laboratoire Jean Alexandre Dieudonné

The effects induced by long temporal correlations of the velocity gradients on the dynamics of a flexible polymer are investigated by means of theoretical and numerical analysis of the Hookean and FENE dumbbell models in a random renewing flow. For Hookean dumbbells, we show that long temporal correlations strongly suppress the Weissenberg-number dependence of the power-law tail characterising the probability density function (PDF) of the elongation. For the FENE model, the PDF becomes bimodal, and the coil–stretch transition occurs through the simultaneous drop and rise of the two peaks associated with the coiled and stretched configurations, respectively.

Mots clés: Polymers; Coil-stretch transition; Random flows

Domaines: Dynamique Chaotique [nlin.CD]; Dynamique des Fluides [physics.flu-dyn]

Stefano Musacchio, Dario Vincenzi. Deformation of a flexible polymer in a random flow with long correlation time. Journal of Fluid Mechanics, 2011, 670, pp.326-336. ⟨10.1017/S0022112010006385⟩. ⟨hal-00544362⟩