Thermal Conductivity and Viscosity Measurements of Water-Based Silica Nanofluids

Nanofluids are a new class of thermal vectors potentially able to drastically increase the heat transfer properties of base fluids such as water, glycol and oil. Nanoparticles of various materials, size (<100 nm), shapes and concentrations can be added to the base fluid to enhance the transport properties. In particular, the knowledge of thermal conductivity and viscosity is essential to study the effect of nanoparticles on the heat transfer coefficient of the fluid. Here, thermal conductivity and viscosity of nanofluids based on water and SiO2 are measured at nanoparticles concentrations ranging from 1% to 54% by weight and temperatures between 10°C and 70°C. After a discussion of the results obtained, the experimental data are used to evaluate the thermal heat transfer capability of water-SiO2 nanofluids in comparison with the base fluid, i.e. water, through the Mouromtseff figure numbers for laminar and turbulent flow.