Abstract:
The superiority of nanofluid over conventional working fluid has been well researched and
proven. Newest on the horizon is the hybrid nanofluid currently being examined due to its improved
thermal properties. This paper examined the viscosity and electrical conductivity of deionized water
(DIW)-based multiwalled carbon nanotube (MWCNT)-Fe2O3
(20:80) nanofluids at temperatures and
volume concentrations ranging from 15 ◦C to 55 ◦C and 0.1–1.5%, respectively. The morphology of the
suspended hybrid nanofluids was characterized using a transmission electron microscope, and the
stability was monitored using visual inspection, UV–visible, and viscosity-checking techniques. With
the aid of a viscometer and electrical conductivity meter, the viscosity and electrical conductivity
of the hybrid nanofluids were determined, respectively. The MWCNT-Fe2O3/DIW nanofluids
were found to be stable and well suspended. Both the electrical conductivity and viscosity of the
hybrid nanofluids were augmented with respect to increasing volume concentration. In contrast, the
temperature rise was noticed to diminish the viscosity of the nanofluids, but it enhanced electrical
conductivity. Maximum increments of 35.7% and 1676.4% were obtained for the viscosity and
electrical conductivity of the hybrid nanofluids, respectively, when compared with the base fluid.
The obtained results were observed to agree with previous studies in the literature. After fitting
the obtained experimental data, high accuracy was achieved with the formulated correlations for
estimating the electrical conductivity and viscosity. The examined hybrid nanofluid was noticed to
possess a lesser viscosity in comparison with the mono-particle nanofluid of Fe2O3/water, which
was good for engineering applications as the pumping power would be reduced.
