Advancement of nanofluids in automotive applications during the last few years—a comprehensive review

The present paper focuses on a review recalling the main contributions of studies that involve nanofluids on automotive industry. The novelty of the paper consists on the concise synthesis presented, that highlights new tested nanofluids in several applications in automotive. The review includes critics on the efficiency, the impact on material and the environmental issues when nanofluids are used as fuel. Three main sections are presented, which deploy the use of nanofluids as coolant in a car radiator, addition in the fuel or engine oil and finally the last section reviews the assessment of the wear effects of nanofluids on materials used in a car coolant system and in the car engine. The current review emphasized some major findings and critics: (1) The contradictory conclusions denoted about the effect of volume concentration on pumping power loss and the Nusselt number in a car radiator system. (2) Remarkable discrepancies in the determination of the optimal nanoparticles volume concentration and the precise heat transfer enhancement. (3) The viscosity of a nanolubricant needs a deep analysis to determine the optimal value that ensures the best lubricant film between components in a car engine. (4) Some mechanical problems should be analyzed when using nanofluids in fuel.