Reaction Model Development of Selected Aromatics as Relevant Molecules of a Kerosene Surrogate—The Importance of m-Xylene Within the Combustion of 1,3,5-Trimethylbenzene

Abstract

The development of advanced reaction models to predict pollutant emissions in aero-engine combustors usually relies on surrogate formulations of a specific jet fuel for mimicking its chemical composition. 1,3,5-trimethylbenzene is one of the suitable components to represent aromatics species in those surrogates. However, a comprehensive reaction model for 1,3,5-trimethylbenzene combustion requires a mechanism to describe the m-xylene oxidation. In this work, the development of a chemical kinetic mechanism for describing the m-xylene combustion in a wide parameter range (i.e. temperature, pressure, and fuel equivalence ratios) is presented. The m-xylene reaction sub-model was developed based on existing reaction mechanisms of similar species such as toluene and reaction pathways adapted from literature. The sub-model was integrated into an existing detailed mechanism that contains the kinetics of a wide range of n-paraffins, iso-paraffins, cyclo-paraffins, and aromatics. Simulation results for m-xylene were validated against experimental data available in literature. Results show that the presented m-xylene mechanism correctly predicts ignition delay times at different pressures and temperatures as well as laminar burning velocities at atmospheric pressure and various fuel equivalence ratios. At high pressure, some deviations of the calculated laminar burning velocity and the measured values are obtained at stoichiometric to rich equivalence ratios. Additionally, the model predicts reasonably well concentration profiles of major and intermediate species at different temperatures and atmospheric pressure.

An Upgraded Chemical Kinetic Mechanism for Iso-Octane Oxidation: Prediction of Polyaromatics Formation in Laminar Counterflow Diffusion Flames

“…Results and discussion are centered in two section. In the first one, a preliminary validation using ESTiMatE-Mech [20] is given. In the second one, the procedure to update the mechanism is explained based on a thorough analysis of the mechanism; then, finally, the results are shown for ESTiMatE-Mech_mod.…”

“…The experimental data for species profiles measured in a counterflow burner as well as for laminar flame speeds and ignition delay times will be used for checking the performance of the reaction model ESTiMatE-Mech [20].…”

“…1c), are also well predicted. As the main focus of the current paper is on the analysis of the PAHs, Figure 3 presents the modeling results for the aromatics and PAHs formation for the two non-sooting flames I-Y35-S60 and flame I-Y60-S100 using ESTiMatE-Mech [20]. Figures 3a to 3i show the species concentration profiles vs. temperature profiles for: Benzene (A1), toluene (C7H8), ethylbenzene (ebz), styrene (A1C2H3), indene, naphthalene (A2), acenaphthylene (A2R5), phenanthrene (A3), and pyrene (A4).…”

“…In the present work, a chemical kinetic mechanism called ESTiMatE-Mech [20] was further developed and optimized to allow its description of the combustion of iso-octane for different reactor conditions. ESTiMatE-Mech is 5 © <2023> by ASME.…”

Large Eddy Simulation of Soot Formation in a Real Aero-Engine Combustor Using Tabulated Chemistry and a Quadrature-Based Method of Moments

“…The kerosene fuel (Jet-A1) is represented by a surrogate consisting of 52 vol-% dodecane (C 12 H 26 ), 15.8 vol-% iso-octane (C 8 H 18 ), 12.1 vol-% cyclohexane (C 6 H 12 ), and 20.1 vol-% trimethylbenzene (C 9 H 12 ). The chemical kinetics are modeled with a recently developed mechanism for kerosene surrogates specialized for soot formation [38,39], which is based on a multicomponent reaction mechanism [40]. Subsequently, the calculated flamelets are parameterized by the mixture fraction 𝑍 and the progress variable 𝑌 𝐶 and stored in a manifold.…”