On the similarity between gravity and magneto-gravity convection within a non-electroconducting fluid in a differentially heated rectangular cavity

The magneto-gravity convection induced by a vertical magnetic field gradient applied to a non-electroconducting paramagnetic liquid in a differentially heated rectangular cavity is investigated numerically and experimentally. Due to the magnetic susceptibility temperature dependence of the fluid, the magnetic body force drives a thermoconvective motion in the cavity. Depending on the sign of the magnetic gradient, the vertical magnetic force in the liquid can be parallel or antiparallel to gravity. Hence, buoyancy convection in the cavity results of the combination of the vertical magnetic force and of gravity. Expressed in terms of Nu versus Ra, the experimental and numerical results are compared to the correlation obtained by Catton without magnetic field. Agreement between the two curves clearly points out the similarity between gravity induced convection and magneto-gravity convection. (C) 2004 Elsevier Ltd. All rights reserved.