Viscosity Analysis of Water-based Copper Oxide Nanofluids

In this paper, the effects of weight concentration of nanoparticles and temperature on the viscosity of water-based copper oxide nanofluids have been studied experimentally using analysis of variance (ANOVA)-based two-factor three-level (2³) factorial design. The results show that a maximum increase of 23.12% in viscosity is observed at 30°C temperature as the weight concentration of nanoparticles increases from 0.03 to 0.3wt.%. Whereas the temperature increases from 30 to 60°C, the viscosity decreases up to 46.19% in the case of 0.3wt.% nanofluid. Temperature is found to be more dominant than the concentration of nanoparticles. The optimum value of viscosity (0.513 mPa.s) is found at concentrations of 0.1wt.% and 60°C temperature with an 18.72% enhancement in viscosity as compared to the base fluid. The experimental and model values of viscosity have been compared with the predictions of the proposed equation for viscosity. The experimentally measured results are found near the proposed results whereas the model underestimates the viscosity in the case of all nanofluids. The maximum underestimation of 25.92 % was observed in the case of 0.3wt.% nanofluid at 60°C temperature.