Comprehensive Surrogate for Emulating Physical and Kinetic Properties of Jet Fuels

A comprehensive three-component surrogate for emulating the physical and combustion characteristics of three types of jet fuel, namely, S-8, Jet-A, and RP-3, has been developed by the methodology of directly matching the molecular structure and functional groups. The components of n-dodecane, 2,5-dimethylhexane, and toluene are chosen to provide comparable molecular sizes and the representative functional groups CH3, CH2, CH, and phenyl of the target fuels. Several important physical properties, including molecular weight, hydrogen/carbon ratio, density, specific heat capacity, viscosity, and thermal conductivity of surrogate fuel, are validated under normal conditions (S-8 and Jet-A) and sub- and supercritical conditions (RP-3). In addition to the detailed comprehensive surrogate chemistry, two skeletal kinetic mechanisms reduced by the path flux analysis scheme are also conducted. The comparisons between the numerical and experimental data, including ignition delay time, flow reactor species profile, and laminar burning velocities, are implemented to elucidate the similarities in the reaction characteristics of surrogates and real fuels. The results show that present surrogate fuels can emulate both the physical and kinetic properties well for these three types of jet fuel.