Analysis of a Surrogate Jet Fuel Skeletal Mechanism With PAH Chemistry

In this work a recently created reduced surrogate A-2 skeletal mechanism with PAH species and a soot model is analyzed against several benchmark cases. A 5-component mixture of N-tridecane, iso-dodecane, butylcyclohexane, 1,2,4-trimethyl benzene and of α-methylnaphthalene is used as the surrogate fuel. As PAH species are critical to accurate soot modeling, the 308 species skeleton mechanism retains PAH species up to cyclo-penta-pyrene (A4R5). A detailed sectional soot model was developed which uses A4R5 as the initial nucleation species and includes numerous PAH species as part of the condensation processes. Surface growth is implemented via the Hydrogen-Abstraction-Carbon-Addition (HACA) method utilizing both acetylene and diacetylene, while oxidation is included with oxidation of OH and O2 molecules. Validation of the skeletal mechanism via laminar burning speed, ignition delay time, and species concentration comparison to experimental values is reviewed. Soot formation of both skeletal and detailed mechanisms is compared in a reactor network model of the CFM56 engine and in counterflow diffusion flame simulations. The results show that the reduced skeletal mechanism is capable of predicting soot with reasonable accuracy.