Effect of electromagnetically driven liquid metal flows on the electric potential difference in a cuboid vessel

Abstract

In this work, we study the effect on the electric potential difference (EPD) of a liquid metal (LM) flow confined in a cuboid vessel. The interaction between a magnetic field (MF) and an electric current density (j0) along the ascending axial direction generates a Lorentz force that stirs the LM producing an MHD flow. The MF is produced by either a single or a pair of NdFeB dipolar permanent magnets. j0 is in the range of 384 to 1153 A m-2. Experimental characterization is done by measuring velocity components using the ultrasound Doppler velocimetry (UDV) technique and measurements of the EPD in terminals of the vessel. Additionally, an MHD model is solved using the COMSOL Multiphysics software. A good agreement between measurements and simulations for the magnetic and velocity fields is obtained. Furthermore, an order of magnitude analysis for the characteristic velocity of the flow and EPD is presented. Comparing with a configuration without magnets, the EPD when one magnet is used reaches 16.8% higher values. In contrast, for a pair of magnets values are 22.9% smaller. This increasing/decreasing behavior for the EPD with the flow patterns could be of interest to applications such as liquid metal batteries.