Cooling is one of the most important processes conditioning proper operation of combustion engines. The development of the higher-power engines entails greater thermal loads, in which in turn require an increased cooling. The use of nanofluids (NFs) with admixture of metallic or nonmetallic nanoparticles (NPs) promises a potential platform for miniaturization of heat exchangers and/or lower energy consumption. This is attributed to an extended surface area related to NPs in the fluid, which allows for increase of thermal conductivity and a considerable increase of the heat transfer coefficient of the fluid with NPs. Their thermo-physical properties, such as particle size, stability, viscosity, dispersion, heat dissipation efficiency, zeta potential and thermal conductivity and also their behavior under different amount in the base fluid are systematically investigated from the point of view of the choice of the best candidate for coolant applied in modern engines. The CuO NPs turn out to be the ones of the most promising additives to the coolant.
The purpose of the review is to give the state-of-art for use of CuO NPs as coolant additive used in combustion engines. The review showed that CuO NPs, next to Al2O3 NPs are the most used additive in engine nanocoolants.