Experimentally determining the thermal properties of NiFe2O4 magnetic nanofluid under suitable stability conditions: Proposal the new correlation for thermophysical properties

Abstract

Magnetic nanofluids are seen as new generation heat transfer fluids because they can act as smart fluids due to the fact that the applied external magnetic field effect can be easily controlled. In this study, NiFe2O4 magnetic nanofluids with 5 different mass ratios between 0.1 and 0.5% were produced with appropriate stability. Firstly, suitable stable nanofluids were prepared and their thermal conductivities, viscosities, specific heats, and densities were experimentally measured at different temperatures (20–60 °C) and concentrations. The obtained data were then used to develop artificial neural network models with MSE and R values of 9.3916E-04 and 0.99969, respectively, and a new concentration and temperature-dependent correlation was obtained for thermal properties. Furthermore, the thermal performance of the nanofluids was evaluated by comparing them with performance criteria such as the PER and Mo values, within the studied concentration and temperature range. The maximum PER value was calculated as 1.185, and the minimum Mo values for laminar flow conditions and turbulent flow conditions were calculated as 1.022 and 1.009, respectively, in the working temperature and concentration range.