skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Ab initio -informed maximum entropy modeling of rovibrational relaxation and state-specific dissociation with application to the O 2 + O system

Abstract

Quasi-classical trajectory (QCT) calculations are used to study state-specific ro-vibrational energy exchange and dissociation in the O 2 + O system. Atom-diatom collisions with energy between 0.1 and 20 eV are calculated with a double many body expansion potential energy surface by Varandas and Pais [Mol. Phys. 65, 843 (1988)]. Inelastic collisions favor mono-quantum vibrational transitions at translational energies above 1.3 eV although multi-quantum transitions are also important. Post-collision vibrational favoring decreases first exponentially and then linearly as Δv increases. Vibrationally elastic collisions (Δv = 0) favor small ΔJ transitions while vibrationally inelastic collisions have equilibrium post-collision rotational distributions. Dissociation exhibits both vibrational and rotational favoring. New vibrational-translational (VT), vibrational-rotational-translational (VRT) energy exchange, and dissociation models are developed based on QCT observations and maximum entropy considerations. Full set of parameters for state-to-state modeling of oxygen is presented. The VT energy exchange model describes 22 000 state-to-state vibrational cross sections using 11 parameters and reproduces vibrational relaxation rates within 30% in the 2500–20 000 K temperature range. The VRT model captures 80 × 10 6 state-to-state ro-vibrational cross sections using 19 parameters and reproduces vibrational relaxation rates within 60% in the 5000–15 000 K temperature range. The developed dissociation model reproducesmore » state-specific and equilibrium dissociation rates within 25% using just 48 parameters. The maximum entropy framework makes it feasible to upscale ab initio simulation to full nonequilibrium flow calculations.« less

Authors:
 [1]; ORCiD logo [2]; ORCiD logo [1]
  1. Purdue Univ., West Lafayette, IN (United States)
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1512881
Alternate Identifier(s):
OSTI ID: 1421171
Report Number(s):
SAND2015-9304J
Journal ID: ISSN 0021-9606; 664890
Grant/Contract Number:  
AC04-94AL85000; Graduate Fellowship
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 144; Journal Issue: 17; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Kulakhmetov, Marat, Gallis, Michael, and Alexeenko, Alina. Ab initio -informed maximum entropy modeling of rovibrational relaxation and state-specific dissociation with application to the O 2 + O system. United States: N. p., 2016. Web. doi:10.1063/1.4947590.
Kulakhmetov, Marat, Gallis, Michael, & Alexeenko, Alina. Ab initio -informed maximum entropy modeling of rovibrational relaxation and state-specific dissociation with application to the O 2 + O system. United States. doi:10.1063/1.4947590.
Kulakhmetov, Marat, Gallis, Michael, and Alexeenko, Alina. Tue . "Ab initio -informed maximum entropy modeling of rovibrational relaxation and state-specific dissociation with application to the O 2 + O system". United States. doi:10.1063/1.4947590. https://www.osti.gov/servlets/purl/1512881.
@article{osti_1512881,
title = {Ab initio -informed maximum entropy modeling of rovibrational relaxation and state-specific dissociation with application to the O 2 + O system},
author = {Kulakhmetov, Marat and Gallis, Michael and Alexeenko, Alina},
abstractNote = {Quasi-classical trajectory (QCT) calculations are used to study state-specific ro-vibrational energy exchange and dissociation in the O2 + O system. Atom-diatom collisions with energy between 0.1 and 20 eV are calculated with a double many body expansion potential energy surface by Varandas and Pais [Mol. Phys. 65, 843 (1988)]. Inelastic collisions favor mono-quantum vibrational transitions at translational energies above 1.3 eV although multi-quantum transitions are also important. Post-collision vibrational favoring decreases first exponentially and then linearly as Δv increases. Vibrationally elastic collisions (Δv = 0) favor small ΔJ transitions while vibrationally inelastic collisions have equilibrium post-collision rotational distributions. Dissociation exhibits both vibrational and rotational favoring. New vibrational-translational (VT), vibrational-rotational-translational (VRT) energy exchange, and dissociation models are developed based on QCT observations and maximum entropy considerations. Full set of parameters for state-to-state modeling of oxygen is presented. The VT energy exchange model describes 22 000 state-to-state vibrational cross sections using 11 parameters and reproduces vibrational relaxation rates within 30% in the 2500–20 000 K temperature range. The VRT model captures 80 × 106 state-to-state ro-vibrational cross sections using 19 parameters and reproduces vibrational relaxation rates within 60% in the 5000–15 000 K temperature range. The developed dissociation model reproduces state-specific and equilibrium dissociation rates within 25% using just 48 parameters. The maximum entropy framework makes it feasible to upscale ab initio simulation to full nonequilibrium flow calculations.},
doi = {10.1063/1.4947590},
journal = {Journal of Chemical Physics},
number = 17,
volume = 144,
place = {United States},
year = {2016},
month = {5}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 26 works
Citation information provided by
Web of Science

Save / Share: