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Title: High fidelity modeling of thermal relaxation and dissociation of oxygen

Abstract

A master equation study of vibrational relaxation and dissociation of oxygen is conducted using state-specific O{sub 2}–O transition rates, generated by extensive trajectory simulations. Both O{sub 2}–O and O{sub 2}–O{sub 2} collisions are concurrently simulated in the evolving nonequilibrium gas system under constant heat bath conditions. The forced harmonic oscillator model is incorporated to simulate the state-to-state relaxation of oxygen in O{sub 2}–O{sub 2} collisions. The system of master equations is solved to simulate heating and cooling flows. The present study demonstrates the importance of atom-diatom collisions due to the extremely efficient energy randomization in the intermediate O{sub 3} complex. It is shown that the presence of atomic oxygen has a significant impact on vibrational relaxation time at temperatures observed in hypersonic flow. The population of highly-excited O{sub 2} vibrational states is affected by the amount of atomic oxygen when modeling the relaxation under constant heat bath conditions. A model of coupled state-to-state vibrational relaxation and dissociation of oxygen is also discussed.

Authors:
 [1]
  1. Department of Aerospace Engineering, University of Michigan, 1320 Beal Ave., Ann Arbor, Michigan 48108 (United States)
Publication Date:
OSTI Identifier:
22482457
Resource Type:
Journal Article
Journal Name:
Physics of Fluids (1994)
Additional Journal Information:
Journal Volume: 27; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-6631
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COLLISIONS; DIATOMS; DISSOCIATION; HARMONIC OSCILLATOR MODELS; HEAT; HYPERSONIC FLOW; OXYGEN; RELAXATION TIME; SIMULATION; VIBRATIONAL STATES

Citation Formats

Andrienko, Daniil A., E-mail: daniila@umich.edu, and Boyd, Iain D. High fidelity modeling of thermal relaxation and dissociation of oxygen. United States: N. p., 2015. Web. doi:10.1063/1.4935241.
Andrienko, Daniil A., E-mail: daniila@umich.edu, & Boyd, Iain D. High fidelity modeling of thermal relaxation and dissociation of oxygen. United States. https://doi.org/10.1063/1.4935241
Andrienko, Daniil A., E-mail: daniila@umich.edu, and Boyd, Iain D. 2015. "High fidelity modeling of thermal relaxation and dissociation of oxygen". United States. https://doi.org/10.1063/1.4935241.
@article{osti_22482457,
title = {High fidelity modeling of thermal relaxation and dissociation of oxygen},
author = {Andrienko, Daniil A., E-mail: daniila@umich.edu and Boyd, Iain D.},
abstractNote = {A master equation study of vibrational relaxation and dissociation of oxygen is conducted using state-specific O{sub 2}–O transition rates, generated by extensive trajectory simulations. Both O{sub 2}–O and O{sub 2}–O{sub 2} collisions are concurrently simulated in the evolving nonequilibrium gas system under constant heat bath conditions. The forced harmonic oscillator model is incorporated to simulate the state-to-state relaxation of oxygen in O{sub 2}–O{sub 2} collisions. The system of master equations is solved to simulate heating and cooling flows. The present study demonstrates the importance of atom-diatom collisions due to the extremely efficient energy randomization in the intermediate O{sub 3} complex. It is shown that the presence of atomic oxygen has a significant impact on vibrational relaxation time at temperatures observed in hypersonic flow. The population of highly-excited O{sub 2} vibrational states is affected by the amount of atomic oxygen when modeling the relaxation under constant heat bath conditions. A model of coupled state-to-state vibrational relaxation and dissociation of oxygen is also discussed.},
doi = {10.1063/1.4935241},
url = {https://www.osti.gov/biblio/22482457}, journal = {Physics of Fluids (1994)},
issn = {1070-6631},
number = 11,
volume = 27,
place = {United States},
year = {Sun Nov 15 00:00:00 EST 2015},
month = {Sun Nov 15 00:00:00 EST 2015}
}