The effect of hybrid nano-additive consists of graphene oxide and copper oxide on rheological behavior of a mixture of water and ethylene glycol

摘要

In the current experimental investigation, the rheological behavior of antifreeze containing a grouping of graphene oxide (GO) and copper oxide (CuO) in temperatures from 25 to 50 degrees C was evaluated. Homogeneous and stable samples with dissimilar solid volume fractions were prepared by dispersing GO and CuO in an equal mixture of water and ethylene glycol consuming a two-step method. The results showed that the base fluid has Newtonian behavior. Such behavior was also observed for the nanofluid with the volume fractions up to 0.4%. However, for higher concentrations than 0.4 vol.%, the viscosity decreased by increasing the shear rate. This demonstrates that the existing hybrid nanofluid has a non-Newtonian behavior (power-law pseudoplastic fluid). Consequently, with the purpose of facilitating the calculation of the viscosity of the nanofluid, a correlation was derived at the temperature range of 25-50 degrees C and the volume fractions of 0.1, 0.2 and 0.4% through a curve fitting technique. In addition, not only the consistency index but also the power-law indexes were gained for non-Newtonian samples exerting the curve fitting technique. Comparisons between the correlation output and experimental data expressed the accurateness of anticipated correlations.