Thermal Conductivity-Based Optimisation of Surfactant on Hybrid Nanofluid

A surfactant is an efficient approach for increasing the stability of nanofluids. However, excessive surfactant degrades the hybrid nanofluid's outstanding thermal conductivity. Additionally, there was only a little research on optimising the amount of surfactant used in nanofluids depending on their thermal conductivity. As a result, it is critical to ensure that the created nanofluid is stable without impairing thermal conductivity. The optimisation was carried out in this study utilising Design Expert 11. Surfactant ratios and the mixing ratio of hybrid nanofluid were employed as variables, while thermal conductivity was used as the response. Additionally, the concentration and temperature of the hybrid nanofluid remained constant at 0.5 vol% and 40 °C, respectively. The results indicate that a 1:10 ratio of surfactant to TiO2 is the optimal proportion for the generated TiO2-GNP hybrid nanofluid. The correct amount of surfactant results in a hybrid nanofluid with high thermal conductivity and good stability.