Effect of magnetic field on natural convection in a C-shaped cavity filled with ferrofluid

摘要

In this paper, natural convection heat transfer has been analyzed for a C-shaped cavity filled with ferrofluid. Cobalt-kerosene ferrofluid is selected here for different solid volume fractions (Φ-0 ～ 0.15). Galerkin weighted residual method is applied to obtain the numerical solution. Simulations are carried out for a wide range of Rayleigh (Ra = 10~3 ～ 10~7) and Hartmann (Ha = 0 ～ 100) numbers for both the ferrofluid and the plain fluid. From this work, it is found that higher Rayleigh number enhances the heat transfer rate significantly, whereas presence of magnetic field tries to retard convection. Moreover, addition of 15% solid volume fraction of nanoparticle can augment the heat transfer rate up to 52.65% at moderate Rayleigh number compared to the base fluid. By an optimization of these parameters, effective heat transfer control equipment can be developed. Results are interpreted on the basis of streamline and isotherm patterns, and average Nusselt number of the heated wall and average fluid temperature of the cavity.