Intensification of heat transfer with an application of strong magnetic gradients

AGH University of Science and Technology, Department of Fundamental Research in Energy Engineering, Faculty of Energy and Fuels, Krakow, Poland

^a Corresponding author: anna.kraszewska@agh.edu.pl

Abstract

Experimental analysis of a strong magnetic field influence on heat transfer by paramagnetic fluid was conducted. A rectangular enclosure, filled with working fluid, was placed inside superconducting magnet’s working section in Rayleigh-Bénard configuration and three temperature differences between heated and cooled walls ΔT= 3, 5, 11 [°C] were applied. On the basis of performed measurements heat transfer analysis in the form of Nusselt number, conduction and convection heat fluxes calculations was conducted. Obtained results demonstrated that Nusselt number strongly depends on the temperature difference between thermally active walls as well as on the magnetic induction applied to the system. An application of external high magnetic field from 0 [T] to 10 [T] caused an increase of the heat transfer rate – about 250% for ΔT = 3 [°C] and over 340% for ΔT = 5, 11 and 20 [°C] and can be successfully implemented to heat transfer intensification for paramagnetic fluids.