Insight into Natural Convection and Magnetic Energy Dynamics within a Triple Enclosure Filled with Ferrofluid

A passive way to control heat transfer through porous media is the use of permanent magnetic field with ferromagnetic fluids as the working fluids. Here, two-energy equation model is applied to model heat transfer inside a Porous separated triple enclosure exposed to permanent magnetic field. Two magnets are located at two positions in the cavity. The bottom wall is kept at a constant hot temperature, while the side walls are cold, and the upper ones are adiabatic. The magnetization of the ferrofluid was modeled by The Langevin function. Finite volume-based finite element method has been used to solve the nonlinear governing equations. Key parameters including magnetic and thermal Rayleigh numbers, dimensionless convection coefficient at two-phase interface, porosity coefficient and Darcy number on combined natural-magnetic heat transfer is investigated. The results indicate that the magnetic convection inhibits the natural one for high Rayleigh. Both the fluid and the solid matrix medium are affected by the interfacial Convection coefficient. Raising the porosity and Darcy number enhances heat transfer, but the effect of the porosity is more limited for low Darcy numbers.