Non-Newtonian Nanoflud Flow and Heat Transfer in a Microchannel filled with aPorous Medium

Abstract

The heat and mass transfer characteristics as well as the hydrodynamical properties of Cas- son nanofluid flow through microchannels in the presence of porous media with non-uniform walls temperature have large scale utilization in industries, engineering and bio-technology. Therefore, this research project considered the analysis of Casson nanofluid flow as well as heat and mass transfer characteristics with variable viscosity. The flow was generated due to the axial pressure gradient, suction/injection and buoyancy forces. The Buongiorno’s nanofluids flow model (two-phase model) was used to examine the effects of the Brownian diffusion and the thermophoresis diffusion of nanoparticles while the Darcy-Forchheimer model was considered to study the interaction between the nanofluid and the porous media. The highly non-linear partial differential equations for continuity, momentum, energy and concentration were formulated, non-dimensionalized and then solved using the implicit sec- ond order accurate finite difference method known as Keller–Box method. Accordingly, the numerical results indicated that both velocity and temperature profiles have shown an in- creasing behavior with increasing values of Pr, Sc and Nt. Moreover, the result revealed that Cf at both sides of the microchannel walls was large for higher vales of A, Ec, F and Re. The Nusselt number at both sides of the microchannel walls has shown an increasing pattern with increasing values of Ec, l and Re whereas both b and lhave indicated opposite effects on the Nusselt number at the left and right walls of the microchan- nel. furthermore, the Sherwood number at both sides of the microchannel walls has shown an increasing pattern with increasing values of Ec, l , Sc and Re.