Magnetic fluid application as a heat carrier in cooling systems under spaceflight conditions
This article presents the results of numerical simulations and experiments on studying mechanisms of heat and mass transfer in magnetic fluids. These substances belong to the class of nanofluids and are being employed as a heat carrier in cooling systems. The inter-particle interactions effect on diffusion processes in magnetic fluid was studied. Numerical experiment has demonstrated the possibility of convective cooling in the absence of gravitational field. The flows' modes and structures in a magnetic fluid in a vertical thin layer being heated from the one wide side, as well as a spherical cavity, being heated from below, were studied. The interaction of thermomagnetic and thermogravitational convective flows in a vertical magnetic fluid layer placed in a transverse magnetic field was being considered. A flat rectangular shape selection for the study is associated with a model of the simplest heat exchange device, as well as for comparing the results with known theoretical calculations in this problem. To study behavior of the inhomogeneously heated magnetic fluid in gravitational and uniform magnetic fields, experiments in a spherical cavity were performed. Besides, with this geometry, the simplest movement is being realized near the stability threshold of mechanical equilibrium when heating from below in the form of a sole whirl, rather than the system of interacting shafts as in the case of the flat layer. The article demonstrates that thermogravitational and thermomagnetic tramsport mechanisms interaction under laboratory conditions leads to the complex behavior of the convective system and, as a consequence, to the heat and mass transfer processes complication. The authors propose the possibility of application of active and passive cooling systems with magnetic fluids onboard a spacecraft under conditions of microgravity. For this, numerical modelling performing of the cooling system is being planned to give estimation of its energy efficiency, as well as performing the full-scale space experiment.