Electronic edition ISSN 1574-0579

Technical framework for studying thermomagnetic convection in an extended closed loop

M. Koskov

Abstract
The focus of this paper is a technical framework for studying thermomagnetic convection of ferrofluids in an extended closed loop that is a thin tube of circular cross-section. In the experiment, a short vertical section of the loop exposed to a nonuniform external magnetic field was heated. The remaining part of the loop was blown with a stream of thermostatic air to provide a constant heat transfer coefficient and an exponential temperature distribution along the tube. The damping decrement of the temperature perturbation was used to get information about the axial heat flux. Test experiments were performed with a colloidal solution of magnetite in moderately concentrated kerosene. It is shown that for Rayleigh numbers of the order of 10³, the thermomagnetic convection mechanism causes a triple increase in heat transfer. Tables 1, Figs 8, Refs 16.