Numerical simulation of the ferro-nanofluid flow in a porous ribbed microchannel heat sink: investigation of the first and second laws of thermodynamics with single-phase and two-phase approaches

In this study, the entropy generation of Fe 3 O 4 –water nanofluid flow in the porous ribbed microchannel heat sink with two approaches is investigated. For modeling, the nanofluid flow inside of porous ribbed microchannel heat sink with two models is classified. The range of Reynolds number and porosity of ribbed blocks is 10 ≤ Re ≤ 80 and 0 ≤ ε ≤ 75 %. The effects of Reynolds number, porosity and compression between microchannel without any rib, microchannel with solid rib and microchannel with LTNE porous rib for two models are investigated. The highest value for the coefficient of heat transfer occurs in the maximum value of volume concentration of nanoparticles, Reynolds number and porosity percent. We realized that, in this investigation, the mixture model represents higher value than single-phase model except in the zero percent of volume fraction of nanoparticles. Also, we showed that the entropy generation increases by increasing the porosity value.