Two-phase modelling of the nanofluid mixed convection in a porous open cavity

The aim of the current work is to study the mixed convection of Fe3O4-water magnetic nanofluid in a heated porous open cavity. Buongiorno's two-phase model is utilised to consider the Brownian and thermophoresis of nanoparticles in the carrier fluid. Using the Darcy-Brinkman and Boussinesq approximations, the governing equations are solved by the finite volume technique, numerically. Numerical computations are performed for various Richardson numbers (Ri = 0.01, 0.1, 1 and 10), Reynolds numbers (Re = 10, 100, 300 and 600), volume fraction of nanoparticle (phi = 0 and 0.06), porosity (epsilon = 0.5, 0.8 and 1) and Darcy numbers (0.0002 <= Da <= 500,000). The nanofluid flow and heat transfer rate are discussed in detail by contour plots of streamlines and isotherms of nanoparticles. Numerical results indicate that increasing Reynolds number increases the average Nusselt number. However, in low Darcy numbers, porosity has no significant effect on the Nusselt number.