Mixed convection Ag-MgO/water hybrid nanofluid flow in a porous horizontal channel

Heat transfer and fluid flow of hybrid nanofluid into horizontal rectangular porous channel is numerically investigated. The Darcy-Brinkman-Forchheimer model is used and the finite volume method is employed to solve the governing equations. The effect of nanoparticle volume fractions ( φ ), permeability (Darcy number Da ) and porosity ( ε ) of porous medium and Richardson number ( Ri ) on the flow field and heat transfer rate are analyzed and commented. The results, presented by streamlines, isotherms, temperature, velocity, and, local, average and normalized Nusselt numbers, reveal the periodic character of the flow in both of space and the time. The flow is characterized by thermoconvective cells which are influenced by the variation of the permeability and the addition of hybrid nanoparticles into the base fluid. The heat transfer rate increases by increasing the permeability and the porosity of porous medium. It enhances for certain nanoparticle volume fractions depending on the Darcy number. The effect of nanoparticles on the enhancement rate of heat transfer mount by increasing Richardson and Darcy numbers.