Nonlinear Brownian dynamics of interfacial fluctuations in a shear flow

Marine Thiébaud (1) , Yacine Amarouchene (2) , Thomas Bickel (2)

1 LIPhy - Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères]
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine

Using Brownian dynamics simulations, we investigate the effect of an external flow on the fluctuations of a liquid–liquid interface for a wide range of shear rates. Although the statistics is Gaussian at low shear, we observe a transition to a nonlinear phenomenology above a critical shear rate. In particular, we show that statistical properties at high forcing share striking similarities with Burgers turbulence. An energy criterion allows us to predict the onset of non-Gaussian statistics. It also provides a simple explanation for the development of shock singularities through the exchange of kinetic energy from regions with positive to negative gradients in the shear direction.

Mots clés: Liquid Films (theory); Turbulence; Soft interfaces; Interfacial phenomena and wetting; Fluids in confined geometries

Domaines: Mécanique statistique [cond-mat.stat-mech]

Marine Thiébaud, Yacine Amarouchene, Thomas Bickel. Nonlinear Brownian dynamics of interfacial fluctuations in a shear flow. Journal of Statistical Mechanics: Theory and Experiment, 2014, 2014 (12), pp.P12011 (1-11). ⟨10.1088/1742-5468/2014/12/P12011⟩. ⟨hal-01119909⟩