Screening chemical kinetic models: Collision limit violations and ultra-fast time scales

Abstract

Detailed chemical kinetic models are widely used in combustion research and many new mechanisms for different fuels and reacting conditions are developed and published 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. In addition, two other online modules are provided to check thermodynamic properties and transport parameters to help the kinetic model developers determine the sources of collision limit violations (CLV). Furthermore, issues related to unphysically fast time scales can remain an issue even if all bimolecular reactions are within collision limits. Therefore, we also present a procedure to screen ultra-fast reaction time scales using computational singular perturbation (CSP). For demonstration purposes, three versions of the rigorously developed AramcoMech are screened for collision limit violations and version 2.0 for ultra-fast time scales.