Curve fitting on experimental data of a new hybrid nano-antifreeze viscosity: Presenting new correlations for non-Newtonian nanofluid

摘要

In this paper, the rheological behavior of a mixture of water and ethylene glycol containing a combination of multi-walled carbon nanotubes and aluminum oxide in a temperature range of 25 to 50 degrees C was investigated experimentally. Homogeneous and stable samples with different concentrations were made by suspending carbon nanotubes and aluminum dioxide in a 50-50 mixture of water and ethylene glycol using a two-step method. The viscosity of nanofluid samples at different shear rates was measured by the DV-I PRIME Brookfield digital viscometer, which uses a rotating cylinder method. The results showed that, despite the Newtonian behavior of the base fluid, all nanofluid samples showed a non-Newtonian behavior. It was also observed that non-Newtonian behavior of nanofluid follows the Power law model. Thus, using the curve fitting, the consistency index and the power law index were obtained. Moreover, mathematical correlations were proposed as a function of temperature and volume fraction for obtaining consistency index and the power-law index. Comparisons showed the accuracy of proposed correlations. (C) 2019 Elsevier B.V. All rights reserved.