A Review on some Viscosity Models for CuO-water Nanofluid and their effects on Thermal Enhancement for Automotive Applications

A significant number of studies pertaining to the use of Al2O3-water and CuO-water as nanofluids are available in the literature. Almost all CuO-water nanofluid studies emphasize the thermal performance enhancement due to the CuO nanoparticles. There are still some open discussions among the nanofluids results available in literature. One relevant aspect relates the standardization of the nanofluid preparation method. Nanofluid preparation uses either the single-step method or two-step method. However, the parameters and method preparations are unique for each published study. In order to reach the expected thermal performance enhancement, every study consider different boundary conditions in nanofluid preparation. Nanofluid preparation represents a critical aspect for thermal performance enhancement. A stable nanofluid with low level of sedimentation can increase the thermal performance enhancement. Thus, there is a correlation between the nanofluid viscosity and the aggregation. The cooling automotive systems are potential applications for nanofluids produced with deionized water (Di-water) and ethylene glycol (EG) mixtures. Many studies considered the use of CuO nanoparticles into Di-water/EG mixtures for thermal enhancement purposes. This study provides a review on viscosity models, by comparing the impact of nanofluid preparation parameters on thermal performance enhancements for automotive cooling systems.