An analysis of unsteady thermal convection of paramagnetic fluid in cubical enclosure under strong magnetic field gradient

The experimental studies of the flow and heat transfer of a paramagnetic fluid inside a cubical enclosure in a configuration heated from below and subjected to various strong non-uniform magnetic field gradients are presented. In contrast to the previously reported studies in literature, which observed solely laminar flow regimes, the appearance and sustenance of the periodic- and fully transient – flow motions for the very first time were investigated. This was consequence of using significantly stronger magnetic field gradient (up to 900 T2/m) than those used in previous studies (up to 200 T2/m). The fluid flow was studied at two Rayleigh numbers: 7.89·105 and 1.86·106. Non-monotonic behaviour of flow with increase of imposed magnetic field gradients was observed for both cases. Detailed analysis (Fast Fourier Transform) of temperature time series has been reported.