Reaction kinetic numerical simulation of combustion process and emission formation in aero-engine combustor

A detailed mechanism and a reduced reaction mechanism (including 50 species and 118 reactions) of n-decane which was chosen as a surrogate fuel for kerosene were built.The ignition delay time of this surrogate fuel in the shock tube and the process of premixed combustion in the premixed burner were simulated by adopting the detailed and reduced reaction mechanisms,and the simulated results were compared with the experimental data.Furthermore,the flow characteristics and the reaction kinetic characteristics of combustion process and the formation of emissions and active species in a tube of the annular tube combustor were analyzed by combining this reduced reaction mechanism with the CFD computational software(Fluent),and the computational results were compared with that of the global reaction mechanism of C₁₂H₂₃ fuel.The results show that the ignition delay time,the shape of the profiles of the mole fractions of the reactants,the major combustion products simulated using the reduced mechanism agree well with the experimental data.Furthermore,compared with the global reaction mechanism of C₁₂H₂₃ fuel,when adopting the reduced reaction mechanism of n- decane,temperature field accords well with the practical situation,and the computational outlet temperature is closer to the design outlet temperature of the combustor.At the same time,the process of fuel low temperature decomposition and formations of pyrolysis products,active species and main emissions are better detailedly understood.