Research progress of improving nanofluid fuel performance

Nanofluid fuel is a kind of suspension liquid, which is made by adding nanoparticles into the liquid fuel. It has advantages of high energy density and shorter ignition delay, and thus shows the potential of improving the burning characteristics of the fuels. To further improve the performance of nanofluid fuels and explore more effective performance control methods, the progress of research on nanofluid fuels in recent years at home and abroad is briefly reviewed in this work. Researches on the improvement of the stability performance, rheological performance, evaporation performance, ignition performance and combustion performance of nanofluid fuels are introduced, and the corresponding tailoring methods and mechanisms are analyzed. Adding surfactant and surface coating are effective methods to improve the stability of nanoparticles in the fuel. The methods of regulating ignition and combustion performance are based on improving the heat conduction and absorption capacity of droplets and promoting the heat release of metal particles, which mainly include nano-metal particles, nano-metal oxides, and new metastable intermixed composites. The existing problems in current research are summarized. More importantly, it is pointed out that the future study of nanofluid fuels should focus on broadening the boundary of the fuel, exploring new surfactants, and establishing the theoretical framework of ignition and combustion.