Nanofluids offer superior heat transfer compared to conventional automotive coolants, with further improvements achievable through particle hybridization and particle shape effects. This study numerically investigates the thermal performance of a ruffled-fin radiator using ternary hybrid nanofluids composed of ZnO, Al2O3, TiO2, MWCNTs, graphene, Fe, Cu, and Ag nanoparticles at varying volume fractions. Combinations such as Fe/Cu/Ag, Fe/Cu/ZnO, and Ag/Al2O3/TiO2 enhanced convective heat transfer, as reflected in increased Nusselt numbers and overall heat transfer coefficients. Increasing the volume fraction reduced outlet coolant temperature, with an optimal nanofluid achieving a 44.6% temperature drop at the engine outlet. The performance index, defined as a composite measure of heat transfer and cooling efficiency, decreased by 5.8-11.7% across the eight ternary nanofluids, with non-metallic oxides exhibiting the smallest reduction. These results demonstrate the role of ternary hybrid nanofluids in improving radiator cooling while indicating efficiency trade-offs at higher volume fractions.
Oshionebo et al. (2025) studied this question.