MHD Mixed Convection Inside Double-wall-driven Enclosure Containing Ag-water Nanofluid and Center Heater

Simulations are performed to examine the mixed convection flow behavior within a wall-driven square enclosure containing Ag-water nanofluid. The enclosure is assumed to contain a center heater and is acted on by a longitudinal magnetic field. The resulting magnetohydrodynamic (MHD) flow equations are solved using the finite volume method (FVM) and SIMPLE algorithm for two orientations of the heater, namely horizontal and vertical. The simulations focus specifically on the effects of the heater length, Richardson number (Ri = Gr/Re, where 102 ≤ Gr ≤ 106 and Re = 100), the Hartmann number (0 ≤ Ha ≤ 100), and the Ag nanoparticle volume fraction (0.0 ≤ ϕ ≤ 0.09) on the fluid flow and heat transfer performance within the enclosure. It is shown that, irrespective of the heater orientation, the heat transfer rate increases with an increasing heater length. However, as the magnetic field strength increases, the convection effect is suppressed, and hence the heat transfer performance reduces. Also, it is found that heat transfer rate increases with an increasing solid volume fraction of Ag nanoparticles into the pure water.