Thermomagnetic convection control strategies for electromagnetic devices immersed in a ferrofluid

This paper presents new control strategies for improving the thermomagnetic convection intensity in electromagnetic devices. Thesystem consists of a winding prototype immersed in a ferrofluid solution based on magnetic nanoparticles. The whole system isexposed to an external magnetic field generated by an annular magnet placed against the tank. When possible, experimental resultsare compared with numerical ones obtained using the finite element method in a 2D-axisymmetric setting. The first control strategyconsists of assessing the impact of Curie’s temperature on heat removal. Numerical calculations show that the maximum windingtemperature decreases by 2.2 °C with the use of magnetic nanoparticles with the lowest Curie temperature. Employing an auxiliarymagnetic field may be another method for monitoring the thermomagnetic convection. The number of streamlines increases in theupper part of the tank due to the intensification of the magnetic force at the top of the winding. It is shown that magnetization,orientation, and location of the magnet play a crucial role in maximizing heat transfer inside the tank. The experiment shows atemperature decrease of 9°C at the top of the winding if an external magnetic field is applied.