Methane skeletal mechanism for space propulsion applications

A skeletal chemical kinetic model for ??₄/air combustion with 100 reactions and 24 chemical species was developed from the detailed mechanism, with 42 species and 298 reactions. The mechanism reduction was performed with the multi target reduction strategy realized in the in-house developed DLR RedMaster code. RedMaster is able to analyze the different chemical processes (ignition delay time and laminar flame speed) in the given time and height points. The applied reduction strategy and selection of experimental targets for model analysis allowed to construct skeletal mechanism that did not lose the predictive capabilities of input model and can be used for modeling of experimental data, which were not included in reduction loop. The obtained reduced model describes satisfactory experimental data for ignition delay and flame speed under conditions: p₅ = 1-50 bar, T₅= 940K - 210K, Φ = 0.5-2; p = 1-60 bar, T₀= 300K, Φ = 0.6-1.4. Some problems related to reaction mechanism reduction are analyzed.