Studies on Al2O3, CuO, and TiO2 water-based nanofluids: A comparative approach in laminar and turbulent flow

Resumo

The Prandtl number, Reynolds number and Nusselt number are functions of thermophysical properties of nanofluids, and these numbers strongly influence the convective heat transfer coefficient. The thermophysical properties vary with volumetric concentration of nanofluids. Therefore, a comprehensive analysis was performed to evaluate the effects on the performance of nanofluids due to variations of density, specific heat, thermal conductivity and viscosity, which are functions of nanoparticle volume concentration. Three metallic oxides, aluminum oxide (Al₂O₃), copper oxide (CuO), and titanium dioxide (TiO₂), dispersed in water as the base fluid were studied. A convenient figure of merit, known as the Mouromtseff number, is used as a base of comparisonfor laminar and turbulent flows. The results indicated that the considered nanofluids can successfully replace water in specific applications for a single-phase forced convection flow in a tube.