Thermophysical Surrogate Model Development of Transportation Kerosene Fuels

E. Khani and C. P. Chen
Department of Chemical and Materials Engineering The University of Alabama in Huntsville Huntsville, USA
chenc@uah.edu
Abstract
Aviation kerosene fuels such as Jet-A and JP-8 are traditionally used in gas turbines and jet engines. Recently, these aviation fuels are also considered for ground vehicles utilizing diesel engines. The spray combustion process in diesel engines requires detailed characterization of the ignition delay of the fuels used for the preparation of stratified fuel-air charge. Ignition delay phenomenon is dominated by the fuel heating and evaporating spray process. For computational modeling of the spray combustion processes, it is essential to have accurate values of fuel
thermo-physical properties. Real kerosene fuels are typically composed of hundreds to thousands of components and are not feasible to be used in multicomponent spray combustion calculations. The object of this study is to develop a surrogate fuel, composed on a few components, to mimic the heating and evaporating behaviors of the real fuel. To this end, we have utilized a recently developed inversed batch distillation methodology to select a group hydrocarbon species that closely match the experimental distillation curve of a Jet-A blend. In addition, eight target properties including cetane number (CN), molecular weight, lower heating value (LHV), H/C ratio, density, viscosity, surface tension, and thermal conductivity are also accurately matched.
From the hydrocarbon groups of typical kerosene fuels of linear paraffins, cyclo-paraffins and aromatics, we have identified the 4-componet surrogate fuel as: n-dodecane/iso-cetane/trans- decalin/toluene (mole fraction: 0.29/0.14/0.32/0.25). Detailed methodologies and data validations will be presented and discussed.