Ferrohydrodynamic capillary convection

Abstract

In this work consideration is given to capillary convection on ferrofluids owing to the concentration gradient generated when a non-homogeneous magnetic field is applied. It is known that mass transfer along an interface between two fluid can appears due to a gradient of the surface tension in the so-called Marangoni effect (or Gibbs-Marangoni effect). Because the surface tension is both thermal and concentration dependent, Marangoni convection can be induced either by a thermal or a concentration gradient, where in the former case is generally referred as thermocapillary convection. On the other hand, it is theoretically and experimentally demonstrated that a ferrofluid under the action of a non-homogeneous magnetic field can induces a concentration gradient of suspended magnetic nanoparticles, and also, it has been measured a continuous increase of the surface tension with increasing the concentration of magnetic nanoparticles, therefore, taking into account the mentioned facts, ferrohydrodynamic capillary convection could be generated in this kind of fluids. Utilizing a simplified physical model, the capillary motion was investigated.