Influence of a horizontal magnetic field on the natural convection of paramagnetic fluid in a cube heated and cooled from two vertical side walls

A cube was filled with an aqueous solution of glycerol with the addition of gadolinium nitrate hexahydrate to make the working fluid paramagnetic. A very small amount of liquid crystal slurry was then added in order to visualize the local temperature inside the enclosure. One vertical wall of the cube was uniformly heated by nichrome wire from a DC power supply while the opposite one was cooled by cold water flowing from a thermostatic circulator. The system was placed close to the solenoid of a superconducting magnet which was horizontally oriented. Two cases were considered in the experiment: the first with the cooled wall close to the solenoid and the second with the heated wall close to the magnet's electric multi-wires. Natural convection was investigated for both cases: first without a magnetic field and second with various strengths of magnetic force acting on the system. The experimental results showed clearly suppression and enhancement of natural convection. Corresponding numerical computations were carried out for comparison with the experimental data. For this purpose, isotherms of the experimental data were extracted from the color images using the Particle Image Thermometry method and were compared with the numerical results. (c) 2007 Elsevier Masson SAS. All rights reserved.