Examination of water dissociation models in shock heated air

Deborah A. Levin, Sergey F. Gimelshein, Natalia E. Gimelshein

Research output: Contribution to journalArticlepeer-review


A semiclassical molecular dynamics approach is used to model the dissociation of water to form the hydroxyl radical. The unimolecular dissociation of water is utilized to compote the probability of reaction, as well as to determine the product OH translational, vibrational, and rotational energy distributions. The flow regime of interest is that between 80 and 100 km, so that a rarefied gasdynamics technique must be used. The molecular dynamics probabilities of reactions and product distributions are, therefore, used in the direct simulation Monte Carlo method to model spatial distribution and temperatures of OH in the bow shock of a 5-km/s vehicle. The fraction of translational energy transferred to internal water energy during dissociative collisions was parameterized. The rates of OH production predicted by the molecular dynamics model are approximately a factor of five lower than those predicted by the total collisional energy model for 10% energy transfer and are approximately equal for 100% energy transfer.

Original languageEnglish (US)
Pages (from-to)251-260
Number of pages10
JournalJournal of thermophysics and heat transfer
Issue number2
StatePublished - 2002
Externally publishedYes

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Aerospace Engineering
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes
  • Space and Planetary Science


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