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arXiv · 2006.10426

Heavy-Impact Vibrational Excitation and Dissociation Processes in CO$_2$

João Vargas·Bruno Lopez·Mário Lino da Silva
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Abstract

A heavy-impact vibrational excitation and dissociation model for CO$_2$ is presented. This state-to-state model is based on the Forced Harmonic Oscillator (FHO) theory which is more accurate than current state of the art kinetic models of CO$_2$ based on First Order Perturbation Theory. The first excited triplet state $^{3}$B$_{2}$ of CO$_2$, including its vibrational structure, is considered in our model, and a more consistent approach to CO$_2$ dissociation is also proposed. The model is benchmarked against a few academic 0D cases and compared to decomposition time measurements in a shock tube. Our model is shown to have reasonable predictive capabilities, and the CO$_2$ $+$ O $\leftrightarrow$ CO $+$ O$_2$ is found to have a key influence on the dissociation dynamics of CO$_2$ shocked flows, warranting further theoretical studies. We conclude this study with a discussion on the theoretical improvements that are still required for a more consistent analysis of the vibrational dynamics of CO$_2$, discussing the concept of vibrational chaos and its possible application to CO$_2$. The necessity for further experimental works to calibrate such state-to-state models is also discussed, with a proposed roadmap for novel experiments in shocked flows.

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João Vargas, Bruno Lopez, Mário Lino da Silva. 2020-06-18. Heavy-Impact Vibrational Excitation and Dissociation Processes in CO$_2$. https://doi.org/10.1021/acs.jpca.0c05677

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