Heat transfer improvement of antifreeze by changing it to hybrid nanofluid: effects of hybrid magnesium oxide-graphene oxide nanopowders

Hybrid nanofluids consisting of two or multiple nanoparticles have received much attention in recent decades. In this study, the rheological behavior of magnesium oxide (MgO) and graphene oxide (GO) nanoparticles which are dispersed in the water-ethylene glycol base fluid is investigated, experimentally, as a new hybrid nanofluid. The effect of volume fraction of nanoparticles (phi) and temperature on the thermal conductivity (k(nf)) of the MgO-GO/water-ethylene glycol hybrid nanofluid is studied. The two correlations are presented for predicting the thermal conductivity. According to the results, the thermal conductivity increased by increasing the volume fraction and temperature. A maximum thermal conductivity improvement of 8.8% is obtained at phi = 0.2% and 60 degrees C. The margin of deviation of 0.507752 and 0.46812%, respectively, for the first and second correlations indicated the accuracy of the proposed correlations. At 20 degrees C, the relative thermal conductivity improves by 2.6%, and at 60 degrees C, the thermal conductivity improves by 5.4% compared to the base fluid. A comparison of the results obtained from these two correlations and experimental results with the theoretical approach (Lu-Lin model) indicated a significant difference between the results.

Automated summary

The study experimentally investigated the rheological behavior of MgO and GO nanoparticles dispersed in a water-ethylene glycol base fluid, and studied the effect of volume fraction and temperature on the thermal conductivity of the hybrid nanofluid. The results showed an increase in thermal conductivity with increasing volume fraction and temperature under certain conditions. The proposed correlations showed small deviations from the experimental results, indicating the accuracy of the correlations.