Simulation of water-graphene oxide two-phase nanofluid flow in a porous ribbed microchannel by considering heat transfer and particle migration

This study explores the effects of nanofluids, used as a dense discrete two-phase system with nanoparticle volume fractions (ϕ) ranging from 0 to 3%, on heat transfer in a ribbed microchannel with a porous medium. Key parameters such as rib angle, Darcy number, and Reynolds number were analyzed for their effect on heat transfer and particle migration. Results indicate that increasing the Darcy number from 0 to 1.883e-4 at a 30° angle and ϕ=3 % raised the Nusselt number from 1.8235 to 2.0376 while increasing the Reynolds number from 10 to 1000 at a 30° angle and the same ϕ raised the Nusselt number from 2.1030 to 3.7519. The maximum Nusselt number observed was 3.9047 for a microchannel with 90° ribs, Reynolds number of Re=1000, ϕ=3 %, and a Darcy number of 7.533e-4. Conversely, the results show that increasing the ϕ also increases fluid density and relative viscosity, leading to higher kinetic energy and maximum flow velocity in the microchannel. Finally, the results revealed that in the presence of a porous medium with a Darcy number of 1.883e-4, for micro-ribs with an angle of 90°, Re=10, and ϕ=1%, the value of the friction factor increases from 0.5956 to 0.9495.