Preparation and properties of high-energy-density aluminum/boroncontaining gelled fuels

Energetic nanofluid fuel has caught the attention of the field of aerospace liquid propellant for its high energy density(HED), but it suffers from the inevitable solid-liquid phase separation problem. To resolve this problem, herein we synthesized the high-Al-/B-containing(up to 30%(mass)) HED gelled fuels, with low-molecular-mass organic gellant Z, which show high net heat of combustion(NHOC), density, storage stability, and thixotropic properties. The characterizations indicate that the application of energetic particles to the gelled fuels obviously destroys their fibrous network structures but can provide the new particle-gellant gelation microstructures, resulting in the comparable stability between 1.0%(mass) Z/JP-10 + 30%(mass) Al or B and pure JP-10 gelled fuel. Moreover, the gelled fuels with high-content Al or B exhibit high shear-thinning property, recovery capability, and mechanical strength, which are favorable for their storage and utilization. Importantly, the prepared 1.0%(mass) Z/JP-10 + 30%(mass) B(or 1.0%(mass) Z/JP-10 + 30%(mass) Al) shows the density and NHOC 1.27 times(1.30) and 1.43 times(1.21)higher than pure JP-10, respectively. This work provides a facile and valid approach to the manufacturing of HED gelled fuels with high content of energetic particles for gel propellants.

High-energy-density gelled fuels with high stability and shear thinning performance

Gelled fuels are the very promising propellants for new-generation rocket and ramjet propulsion.Here we report a new type of low-molecular mass organic gellant(Z),and prepared four kinds of stable gelled fuels based on HD-01,HD-03,RP-3 and QC liquid fuels,with the critical gellant concentration less than 1%(mass).The characterizations show that the gellant can form 3D network structure,via hydrogen bonding,π-πstacking and van der Waals forces,to fix fuel molecules during the formation of gelled fuels.So,the gelled fuels show high stability,with the remaining gel mass of 0.25%(mass)Z/HD-01 more than 90%even at high centrifugal speed of 7500 r·min^(-1),but the rheological property test shows that all gelled fuels have obvious shear thinning property,which benefits its storage in gelled state while supply in liquid state.The gelation of liquid fuels by gellant Z can increase the volumetric net heat of combustion(for HD-01,it increases from 39.58 MJ·L^(-1) to 40.76 MJ·L^(-1) with 1%(mass)Z),and liquefied gelled fuels show the comparable ignition delay time with the pristine liquid fuels.So,the gelled fuels made by gellant Z have better stability,shear thinning and combustion performances,which have great potential for the practical application.

Review on design, preparation and performance characterization of gelled fuels for advanced propulsion

With the increasing demand for high-performance and safe fuels in aerospace propulsion systems,gelled fliels have attracted increasing attention.Because of their unique structure,gelled fuels exhibit the advantages of both solid and liquid fliels,such as high energy density,controllable thrust and storage safety.This review provides an overview on design,preparation and performance characterization of gelled fuels.The composition,preparation process and gelation mechanism of gelled high-energy-density fuels are described.Considering these aspects,the rheology and flow behavior of gelled fuels is summarized in terms of the shear thinning property,dynamic viscoelasticity and thixotropy.Moreover,the progress of atomization of gelled fuels is reviewed with a focus on the effect of atomizing nozzles.In addition,the experiments and theoretical models of single droplet combustion and combustor combustion are described.Finally,research directions for the development and application of gelled fuels are suggested.

Development of High-Energy-Density Liquid Aerospace Fuel:A Perspective

Aerospace aircraft has significantly improved the life quality of human beings and extended the capability of space explosion since its appearance in 1903,in which liquid propellants or fuels provide the key power source.For jet fuels,its property of energy density plays an important role in determining the flight range,load,and performance of the aircraft.Therefore,the design and fabrication of high-energy-density(HED)fuels attract more and more attention from researchers all over the world.Herein,we briefly introduce the development of liquid jet fuels and HED fuels and demonstrate the future development of HED fuels.To further improve the energy density of fuel,the approaches of design and construction of multi-cyclic and stained molecule structures are proposed.To break through the density limit of hydrocarbon fuels,the addition of energetic nanoparticles in HED fuels to produce nanofluid or gelled fuels may provide a facile and effective method to significantly increase the energy density.This work provides the perspective for the development of HED fuels for advanced aircrafts.