A review on thermo-physical properties and heat transfer applications of single and hybrid metal oxide nanofluids

Numerous investigators have explored nanofluids extensively for different types of nanomaterials either the single nanoparticles or hybrid types. This is due to their advantages in thermal properties together with its contribution to the enhancement of heat transfer performance. This paper highlights a complete assessment on thermo-physical properties of single and hybrid metal oxide nanofluids and their heat transfer applications. The paper presents an overview of the thermo-physical properties characterizations namely thermal conductivity, dynamic viscosity, density and specific heat. Furthermore, summaries on the performance of forced convection heat transport and recent developments of the oxide nanofluids are presented. The numerical and experimental studies related to forced convection heat transfer using oxide nanofluids were presented. The thermal conductivity of oxide nanofluids was improved to a maximum of 40% enhancement in the literature. Meanwhile, the heat transfer augmentation up to 60% was reported by various studies. Most of the literatures confirmed the capability of nanofluids to improve the heat transfer efficiency and simultaneously insignificant increments in pressure drop. Hence, the oxide nanofluids are recommended for applications in various engineering systems.