Effect of MHD on heat transfer through ferrofluid inside a square cavity containing obstacle/heat source.

This article contains numerical simulations of the influence of external magnetic field on free convection heat transfer in ferrofluid flow through a square cavity filled with water based ferrofluid when a heated square blockage with different aspect ratios (0.25 ≤ A/H ≤ 0.5 ) is placed at the centre of enclosure. Vertical boundaries of enclosure are assumed insulated, top horizontal wall is taken as cold while bottom horizontal wall is heated uniformly. The square obstacle is present at the centre of cavity which also serves as heat source in fluid. The mathematical model is presented in the form of nonlinear PDE's, which are solved using Galerkin finite element method. Results are shown for wide ranges of physical parameters like Rayleigh, Prandtl and Hartmann numbers etc. The heat and flow structures are noticed to be significantly dependent on strength of magnetic field, Rayleigh number and concentration of ferroparticles present in the base fluid. [ABSTRACT FROM AUTHOR]