On Simulation of Double-Diffusive Natural Convection in a Micropolar Nanofluid Filled Cubic Cavity

摘要

The heat and mass transfer characteristics of a micropolar nanofluid-filled cubic cavity are investigated with different types of nanoparticles (Al_2O_3, TiO_2, Cu and Ag). Pure water is assumed as the base fluid. The governing equations are simplified by means of vorticity-vec-tor potential formulation and subsequently solved numerically using the finite volume method. The influences of relevant parameters on heat and mass transfer characteristics are well explored and the results show that for the micropolar nanofluid model both heat and mass transfer rates and the three-dimensional character of the flow are smaller compared with that of a pure nanofluid model. It is also found that the rate of heat and mass transfer decreases with an increase in vortex viscosity parameters as well as volume fractions. The enhancement in the volume fraction of nanoparticles weakens both flow strength and three-dimensional nature of the flow, which are more prominent in the thermal buoyancy dominated flow. The average Nusselt and Sherwood numbers decrease with the increase in the volume fraction of nanoparticles resulting in a significant enhancement in thermal properties of nanofluids with elevated heat and mass transport features. The effects of type of nanoparticles on the rate of heat and mass transfer and flow structure are analyzed.