Design and synthesis of nanofluid fuels

With the development of nanotechnology, energetic nanoparticles (NPs) have been used in solid propellant to increase the energy content, but for liquid fuel, the addition of such NPs is still challenging. Nanofluid fuels (containing energetic NPs in hydrocarbon fuels), combining the advantages of metal fuels and high-energy-density (HED) hydrocarbon fuels, are drawing more and more attention in the field of HED fuels. In this chapter, we comprehensively summarized the synthesis and preparation method of nanofluid fuels and ways to enhance and evaluate the stability of nanofluid fuels; particularly we will introduce typical high-energy nanofluid fuels with boron and aluminum NPs. Although the nanofluid fuels has higher volumetric heating value, shorter ignition delay, and lower ignition temperature, the suspension stability of nanofluid fuels is one of the main factors restricting its industrial application. Gelling of fuels is an effective way to maintain and stabilize nanofluid fuels. So, the chapter gives an overview of the formulation and preparation of gelled fuels. Furthermore, the search progress on the characterizations of gelled fuels is also reviewed in this chapter, including rheology and flow behavior, atomization and spray behavior, and combustion behavior.