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Screening gas‐phase chemical kinetic models: Collision limit compliance and ultrafast timescales

Yalamanchi, Kiran K.; Tingas, Efstathios?Al; Im, Hong G.; Sarathy, S. Mani


Kiran K. Yalamanchi

Hong G. Im

S. Mani Sarathy


Detailed gas‐phase chemical kinetic models are widely used in combustion research, and many new mechanisms for different fuels and reacting conditions are developed each year. Recent works have highlighted the need for error checking when preparing such models, but a useful community tool to perform such analysis is missing. In this work, we present a simple online tool to screen chemical kinetic mechanisms for bimolecular reactions exceeding collision limits. The tool is implemented on a user‐friendly website,, and checks three different classes of bimolecular reactions; (ie, pressure independent, pressure‐dependent falloff, and pressure‐dependent PLOG). In addition, two other online modules are provided to check thermodynamic properties and transport parameters to help kinetic model developers determine the sources of errors for reactions that are not collision limit compliant. Furthermore, issues related to unphysically fast timescales can remain an issue even if all bimolecular reactions are within collision limits. Therefore, we also present a procedure to screen ultrafast reaction timescales using computational singular perturbation. For demonstration purposes only, three versions of the rigorously developed AramcoMech are screened for collision limit compliance and ultrafast timescales, and recommendations are made for improving the models. Larger models for biodiesel surrogates, tetrahydropyran, and gasoline surrogates are also analyzed for exemplary purposes. Numerical simulations with updated kinetic parameters are presented to show improvements in wall‐clock time when resolving ultrafast timescales.

Journal Article Type Article
Acceptance Date Apr 22, 2020
Online Publication Date May 22, 2020
Publication Date 2020-09
Deposit Date Jun 26, 2020
Journal International Journal of Chemical Kinetics
Print ISSN 0538-8066
Electronic ISSN 1097-4601
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 52
Issue 9
Pages 599-610
Keywords chemical kinetic models; collision limit; combustion; computational singular perturbation; ultrafast timescales
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