Experimental study of rheological behavior of MWCNT (50%)-MgO (50%)/SAE40 hybrid nanofluid: Dynamic viscosity optimization and numerical simulation of turbulent flow

In the present report, the rheological behavior of MWCNT (50 %)-MgO (50 %)/SAE40 hybrid nanofluid (HNF) is investigated experimentally/statistically/numerically in different laboratory conditions. Viscosity is measured at temperatures of T = 25-50 degrees C, solid volume fraction of SVF = 0.0625-1 % and a shear rate of SR = 666.5-9331 s-1. The rheological behavior of the resulting HNF is fitted by the Ostwald-de Waele model. Mathematical calculations based on the power-law model and considering the dependence of viscosity on the SR, show that the HNF is a pseudo-plastic non-Newtonian fluid. The highest values of increase and decrease of viscosity are equal to + 28.70 % (at T = 25 degrees C, SVF = 1 % and SR = 2666 s- 1) and - 5.91 % (at T = 25 degrees C, SVF = 0.0625 % and SR = 3999 s-1, respectively). Based on the response surface methodology (RSM), a mathematical model with a coefficient of determination of 0.9994 is presented to estimate laboratory data. Using a numerical simulation of flow in the branch pipe, the parameters of pressure drop, shear rate and flow velocity compared to the witness fluid flow increase by + 17.05 %, +18.43 %, and + 3.29 %, respectively.

Automated summary

In this report, the rheological behavior of MWCNT (50%)-MgO (50%)/SAE40 hybrid nanofluid (HNF) is investigated experimentally/statistically/numerically. The HNF is found to exhibit pseudo-plastic non-Newtonian behavior, and mathematical models are developed to estimate laboratory data and simulate flow in a branch pipe. The results provide valuable insights into understanding and predicting the rheological behavior of this specific nanofluid.