Kinetic and continuum modeling of high-temperature air relaxation

Sergey F. Gimelshein, Ingrid J. Wysong, Alexander J. Fangman, Daniil A. Andrienko, Olga V. Kunova, Elena V. Kustova, Fabio Morgado, Catarina Garbacz, Marco Fossati, Kyle M. Hanquist

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)
73 Downloads (Pure)


Fully kinetic, vibrationally kinetic, and continuum solvers with varying model fidelity are used in this work to model the high-temperature relaxation of air in 7230 and 15,000 K adiabatic heat baths and a 6 km/s hypersonic flow over a cylinder. The results show significant impact of uncertainties in vibrational relaxation times and reaction rate constants on thermal and chemical relaxation, in particular, on gas temperature and species mole fractions. Most notably, these uncertainties need to be reduced for collisions that include nitric oxide. Order-of-magnitude differences in the nitric oxide dissociation and recombination rates have a large impact on the peak NO mole fraction immediately behind the shock and surface-distributed heat flux, respectively. High-fidelity kinetic and continuum approaches are found to have different reaction channels having the largest effect on species mole fractions and gas temperature: N-2+O exchange and O-2+O dissociation in the former, and NO+O and O-2+N-2 dissociation in the latter.
Original languageEnglish
Pages (from-to)870-893
Number of pages24
JournalJournal of Thermophysics and Heat Transfer
Issue number4
Early online date22 Feb 2022
Publication statusPublished - 31 Oct 2022


  • vibrational-energy transfer
  • Monte-Carlo simulation
  • dissociation
  • rates


Dive into the research topics of 'Kinetic and continuum modeling of high-temperature air relaxation'. Together they form a unique fingerprint.

Cite this