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DOE OSTI · 2475593

Skeletal reaction models for methane combustion

Liu, Yinmin·Babaee, Hessam·Givi, Peyman·Chelliah, Harsha K.·Livescu, Daniel·Nouri, Arash G.
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Abstract

A local-sensitivity-analysis technique is employed to generate new skeletal reaction models for methane combustion from the foundational fuel chemistry model (FFCM-1). Here, the sensitivities of the thermo-chemical variables with respect to the reaction rates are computed via the forced-optimally time dependent (f-OTD) methodology. In this methodology, the large sensitivity matrix containing all local sensitivities is modeled as a product of two low-rank time-dependent matrices. The evolution equations of these matrices are derived from the governing equations of the system. The modeled sensitivities are computed for the auto-ignition of methane at atmospheric and high pressures with different sets of initial temperatures, and equivalence ratios. These sensitivities are then analyzed to rank the most important (sensitive) species. A series of skeletal models with different number of species and levels of accuracy in reproducing the FFCM-1 results are suggested. The performances of the generated models are compared against FFCM-1 in predicting the ignition delay, the laminar flame speed, and the flame extinction. The results of this comparative assessment suggest the skeletal models with 24 and more species generate the FFCM-1 results with an excellent accuracy.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY42 ENGINEERINGForced optimally time dependent modesHigh-pressureLocal sensitivity analysisMethane-air combustionSkeletal model

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Liu, Yinmin, Babaee, Hessam, Givi, Peyman, Chelliah, Harsha K., Livescu, Daniel, Nouri, Arash G.. 2024-09-04. Skeletal reaction models for methane combustion. https://doi.org/10.1016/j.fuel.2023.129581

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