Microscopic mechanism of enhanced thermal conductivity of hybrid nanofluids

The superior thermal conductivity of nanofluids opens up new possibilities for the study of novel heat transfer fluids. In this paper, we use argon-based and glycerol–glycol binary solvent as the base solution, and construct a new type of nanofluid system by adding single and mixed nanoparticles to the solution. We simulated the thermal conductivities to reveal the microscopic mechanism of mixed nanofluids that enhances heat transfer. The results showed that the thermal conductivity of the Cu–Al/Ar hybrid nanofluid was higher than that of the normal nanofluid composed of single Cu or Al particles. Its thermal conductivity was the highest when the volume ratio of Cu to Al was 50%. We obtained maximum improvements of 11.7% and 24.98% in the thermal conductivities of the Al/glycerol–ethylene glycol nanofluid and the Cu–Al/glycerol–ethylene glycol nanofluid, respectively. The findings of this study can provide an important reference for the application of nanofluids to engineering.