关键词: 纳米流体, 数值模拟, 传热, 对流换热系数

Abstract: This paper presented numerical simulation of Fe2O3-water and Al2O3-water nanofluids flow in a constant density of heat flow rate inner grooved copper tube by computational fluid dynamics，and analysis effect of particle concentrations on convective heat transfer coefficient in different Reynolds numbers，various radial and axial locations of tubes. The comparison between the simulated and experimental results showed that the simulation agreed well with the eperimental results. Simulation demonstrated that when Re number was in the range of 1000 to 2000，the heat transfer effects of Fe2O3-water nanofluids were better than that of an equal mass fraction of Al2O3-water nanofluids on the inner grooved copper radial and axial direction. When the mass fraction of Al2O3-water nanofluid was 0.4%，convective heat transfer coefficient increased to 38.8% on the axial direction. The mass fraction of Fe2O3-water nanofluids increased by 0.3%，convective heat transfer coefficient increased up to 26.5%. Re number had stronger influence on convective heat transfer coefficient (up to 78%). The best mass percentage for the convective heat transfer of Fe2O3-water and Al2O3-water nanofluids was around 4%.

Key words: nanofluid, numerical simulation, heat transfer, convective heat transfer characteristics