Eur. Phys. J. Special Topics 219, 71-80 (2013)
https://doi.org/10.1140/epjst/e2013-01782-6

Regular Article

Bénard-Marangoni instability in a viscoelastic ferrofluid

¹ Max-Planck-Institute for Polymer Research, 55021 Mainz, Germany
² Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica, Chile
³ Instituto de Física, P. Universidad Católica de Valparaiso, Casilla 4059, Valparaiso, Chile

^a e-mail: laroze@mpip-mainz.mpg.de

Received: 1 July 2012
Revised: 18 January 2013
Published online: 19 March 2013

Abstract

In this paper we report theoretical and numerical results on convection of a magnetic fluid in a viscoelastic carrier liquid. The viscoelastic properties are given by the Oldroyd model. We impose the lower interface to be rigid, whereas the upper one is free and is assumed to be non-deformable and flat. Also, at the upper interface the surface tension is taken to vary linearly with the temperature. Using a spectral method we calculate numerically the convective thresholds for both stationary and oscillatory bifurcations. The effect of the viscoelasticity and the Kelvin force on the instability thresholds are emphasized.