Resonant enhancement of natural convection in a cubic enclosure under time-periodic magnetizing force

Abstract

A numerical investigation was carried out for natural convection of air (paramagnetic fluid) in a cubic enclosure subjected to constant gravity and time-periodic magnetizing force. Since the magnetizing force expressed as the gradient of magnetic induction squared in each direction, has three-dimensional characteristics, three-dimensional modeling of system would be required to investigate the effect of magnetizing force more accurately. In this study as a sequent research, the basic analysis of Kang and Hyun [16] was extended to the case of three-dimensional and to cases when the magnitude of magnetizing force is varied. Two geometrical configurations for the location of electrical coils, were considered. The amplification characteristics of heat transfer rate in the cube according to the change of the magnitude of magnetizing force, were investigated especially when the resonance occurs. The numerical results showed that the heat transfer is enhanced appreciably by application of large magnitude of magnetizing force. In addition, the results for two- and three-dimensional cases were also compared.