MHD effects on natural convection in a U-shaped enclosure filled with nanofluid-saturated porous media with two baffles.

The present work examines numerically the heat transfer and the buoyancy-driven flow within a U–shaped baffled enclosure filled with a nanofluid-saturated porous medium in the presence of an inclined magnetic field using a finite element scheme. The enclosure bottom wall is heated sinusoidally while the two baffles and the inner walls are maintained at a constant cold temperature. The rest walls of the enclosure are kept adiabatic. The parameters under investigation are Hartmann number (Ha), volume fraction (φ), Darcy number (Da), Rayleigh number (Ra), nanoparticles aspect ratio (AR), and the angle of applied magnetic field (γ). The results are crucial and illustrate that increasing the values of Ra, Da and the nanoparticles volume fraction enhances the heat transfer while the Hartmann number inversely affects the heat transfer augmentation. Moreover, the average Nusselt number (Nu ave) increases by increasing the enclosure aspect ratio. For the geometry under consideration and for a better heat transfer rate, it is recommended to choose an AR = 0.6 at Ha = 0 with a 0.1 vol fraction. [ABSTRACT FROM AUTHOR]