Numerical investigation of combined thermal and magnetic convection ferrofluid flow in a square cavity

The magnetic convection of ferrofluids is of considerable interest in many science and engineering applications. Whereas magnetic convection offerrofluids is apparently greater than ordinary naturalconvection, it can be used for improving the performance of cooling devices. In this paper, thenatural convection heat transfer in a two-dimensionalsquare cavity induced by magnetic field and thermal buoyancy gradients is investigated numerically. Theside walls of the cavity are heated with different temperatures, the top and bottom walls are isolated, and a permanent magnet is located near the bottom wall.The coupled governing equations are transformed into sets of algebraic equations using finite volume method and momentum equations are solved by the SIMPLER algorithm. The magnetization is considered a nonlinear function of magnetic field strength and absolutetemperature. The interaction between magnetic field and thermal buoyancy gradients in a confined domain is investigated. The results of flow and temperature fieldsand the local Nusselt number along the isothermal walls are presented for a typical case. The magnetic Rayleigh number have been varied from 1×104 to 1×107 and the gravitational Rayleigh number varied between 1×107 and 2×1010 to investigate the effect of these twoparameters on the overall Nusselt number. Results show that in the presence of magnetic field, there will be an augmentation in the heat transfer rate.

کلیدواژه ها:

Ferrofluid ، Magnetic convection ، Natural convection ، square cavity