Analysis of combined thermal and magnetic convection ferrofluid flow in a cavity

A numerical analysis of the magnetic gradient and thermal buoyancy induced cavity ferrofluid flow is conducted by a semi-implicit finite element method. The physical model for a square cavity containing two different temperature side walls and a magnet near bottom wall is described by mass, momentum and energy equations. Conditions for the fixed Prandtl number, Rayleigh number and different ferro-hydrodynamic interaction parameter are studied for 5 × 108 ≤ β ≤ 1.6 × 1010. Results show the flow strength increases with the strengthening magnetic field. However, the side-wall heat transfer rate presents a decrease trend with the increase in magnetic field strength, for the magnet located near the bottom central area evokes the circulation to move toward the central portion. In summary, a proper choice of magnet strength and location can adjust the flow field and local heat transfer rate to fit the practical application.