The effect of aspect ratios of rib on the heat transfer and laminar water/TiO2 nanofluid flow in a two-dimensional rectangular microchannel

In this investigation, the computational fluid dynamics of laminar flow and heat transfer in an indented microchannel is investigated. The Water/TiO2 nanofluid has been used as a working fluid. The geometry is a two-dimensional rectangular microchannel with the length of L = 6.3 mm and the height of H = 70 μm. Numerical solution was modeled in the Reynolds numbers of 10, 50, 100 and 300 with volume fractions of 0, 2 and 4% for different aspect ratios AR = 10, 15, 20, 25. The results of this research indicate that the increase of TiO2 nanoparticles causes enhancement of heat transfer, friction factor, and performance evaluation criterion and pressure drop. The results show that the friction factor is approximately independent from the aspects ratio, being dependent on the volume fraction of solid nanoparticles.