Magnetoconvective heat transfer from a cylinder under the influence of a nonuniform magnetic field

Abstract

In this paper, we present experimental results on heat transfer from a nonmagnetic cylinder to a magnetic fluid under the influence of transverse laminar free convection. Measurements are performed in the presence of uniform and nonuniform external magnetic fields; both the fields and their main gradients are directed transversely to the cylinder axis. In zero field the measurement results for both the unsteady and the stationary heat transfer (Ra>10(6)) agree well with the dependences found in the framework of a boundary layer approximation. If a nonuniform magnetic field is applied, the theoretically predicted additive action of gravitation and magnetic convection on the heat transfer intensity is confirmed. In the presence of a uniform field, the changes of heat transfer intensity are insignificant despite the action of strong internal field gradients induced by the nonmagnetic cylinders themselves.