Experimental study of liquid metal heat transfer in a vertical duct affected by coplanar magnetic field: Upward flow

Abstract

Liquid metal cooling is of interest in high heat load applications. Convection of liquid metals in mass force fields, i.e., buoyancy, inertia, magnetic fields, is a problem which is still difficult to predict due to lack of experimental data. There is a special interest in the heat removal systems of a tokamak reactor, where high heat and magnetic fields form unprecedented conditions. Continuing the study of heat transfer in channels with a liquid metal coolant, we consider the upward flow of mercury in a vertical heated rectangular duct located in a strong magnetic field. Specifically, we study experimentally the mercury flow under a coplanar magnetic field (directed transverse to the main flow and along the long side of the duct) for symmetrical (two-sided) and asymmetrical (one-sided) duct heating.The upward flow configuration has enabled us to explore experimentally flow development along the duct using a 3D probe temperature measurement scanning technique. As in the downward flow configuration, the joint action of buoyancy and magnetic forces result in a drastic peculiarity of heat transfer regimes, where buoyancy and magnetic influence can not be neglected. We show that, in contrast to the downward flow, buoyancy effects play a primary role in flow and heat transfer.