679 / 2019-04-29 23:19:01

Investigation and evaluation of thermophysical properties of Al2O3-CuO/EG-water hybrid nanofluids

viscosity; thermal conductivity; CuO-ZnO hybrid nanofluids; mixture ratio

全体主题 > 纳米传热、纳米流体流动和纳米材料

In recent years, research is focused on enhancing the thermo-physical properties of single component nanofluids. Hence, the hybrid or composite nanofluids are developed to enhance the heat transfer performance. In this research, the thermal conductivity and dynamic viscosity of hybrid nanofluids is experimentally investigated. The studied nanofluid was produced using a two-step method by dispersing Al2O3 and CuO nanoparticles in a binary mixture of EG/water (50%:50%). The experiments were conducted for 1.0% mass fraction of Al2O3-CuO nanofluids with different mixture ratios ranged between 40:60 to 60:40, temperature ranged from 25-60oC. The experimental results show that the minimum thermal conductivity for Al2O3-CuO nanofluid was obtained with a ratio of 50:50，at this point, the thermal conductivity only increases by the maximum of 7.96% over the base fluids, while the viscosity increases by 22.2%. In addition, the analysis of dispersion stability shows that the large clusters obtained by particle deposition also affect the reduction of thermal conductivity of the mixed nanofluid, and the large clusters reduce the effective area of metal particles and affect the change of thermal-physical properties. Finally, the thermal sensitivity of Al2O3-CuO mixed nanofluid at each particle mixing ratio was investigated through thermal sensitivity analysis, and the influence of particle mixing ratio and temperature on the thermal sensitivity of mixed nanofluid was observed.