Flow of water-based Cu, CuO, and Al2O3 nanofluids heated with constant heat flux between micropipe

This study aims to analytically measure the fully developed laminar flow and heat transfer the water-based nanofluids, Cu, CuO, and Al2O3, within a micropipe with constant heat flux, under the temperature jump and slip rate boundary conditions. Knudsen number, nanoparticle volumes, and ratios of liquid layer thickness to particle radius are assumed, 0, 0.02, 0.04; 0%, 4%, %8, and 0.1, 0.2, 0.4, respectively. The findings suggest that adding nanoparticles to flow area has significant effect on both the velocity field and the heat transfer. There is a significant decline in the velocity both at the core and on the walls in the velocity area, due to the increase in the solid volume and the ratios of liquid layer thickness to particle radius after adding nanoparticles to flow area, and the increase of Nusselt number is significantly proportional to that of the solid volume and the ratios of liquid layer thickness to particle radius. Among the nanoparticles, Cu, CuO, and Al2O3, used as nanofluids within the micropipe, Cu is found to be the one with the highest heat transfer enhancement, followed by Al2O3, and CuO, respectively.