Numerical Modeling of Ferrofluid Convective Behavior Within an Enclosure Under the Influence of a Magnetic Field

With the goal of improving the performance of cooling systems of magnetic sensors, the effects of adding nanoparticles and employing ferrohydrodynamics (FHD) are studied with numerical simulations. To produce ferrohydrodynamics, a wire near the hot surface is used to produce a varying Kelvin force. To better describe the magnetic force, a ferrofluid consisting of iron oxide and water is used. In the velocity and temperature equations, new terms are added to represent ferrohydrodynamics and buoyancy. To apply such complex physics, the control volume finite element method (CVFEM) is applied, and the equations are written in vorticity form to help remove pressure terms. This modeling approach is validated against previously published work and the results show good agreement. An improvement of 11.65 % in the convection rate is achieved by adding nanoparticles. Considering a higher buoyancy force results in a 118.92 % increase in the Nusselt number Nu. As MnF increases up to 2 × 10³, Nu increases by about 81.88 % at the lowest Rayleigh number Ra. The influence of ferrohydrodynamics on Nu declines as the gravity force increases. The hot surface becomes cooler by about 10 % and 37.5 % when MnF and Ra are increased.