An experimental study on thermal conductivity of F-MWCNTs–Fe3O4/EG hybrid nanofluid: effects of temperature and concentration

In this paper, an experimental study on the effects of temperature and concentration on the thermal conductivity of f-MWCNTs–Fe3O4/EG hybrid nanofluid is presented. The experiments were carried out for solid volume fraction range of 0 to 2.3% in temperatures ranging from 25 °C to 50 °C. The results revealed that the thermal conductivity ratio enhances with increasing the solid volume fraction and temperature. Results also showed that, at higher temperatures, the variation of thermal conductivity ratio with solid volume fraction was more than that at lower temperatures. Moreover, the effect of temperature on the thermal conductivity ratio was more noticeable at higher solid volume fractions. The thermal conductivity measurements also showed that the maximum thermal conductivity ratio was 30%, which occurred at temperature of 50 °C for solid volume fraction of 2.3%. Finally, for engineering applications, based on experimental results, a precise correlation was suggested to predict the thermal conductivity of f-MWCNTs–Fe3O4/EG hybrid nanofluids.