The conventional liquids have some limitations regarding the thermal properties. The nanoparticles addition is one of the techniques which can modify them. In this research, heat transfer coefficient (h) and pressure loss (Δp) of various nanofluids containing Al2O3, SiO2 and MgO nanoparticles dispersed in water in an annular tube with constant wall temperature were numerically considered. According to the literature, five different nanofluid volume concentrations (1%, 2%, 3%, 4% and 5%) were chosen and used. Two models involving the mixture and VOF were applied and their data were compared. The average convective heat transfer coefficient and pressure loss enhanced with volume fraction and Reynolds number (Re) increment (3000
