The Hydrogen-Air Burning Rate Near the Lean Flammability Limit Articles uri icon

publication date

  • May 2009

start page

  • 741

end page

  • 761


  • 4


  • 13

international standard serial number (ISSN)

  • 1364-7830

electronic international standard serial number (EISSN)

  • 1741-3559


  • This paper investigates the inner structure of the thin reactive layer of hydrogen-air fuel-lean deflagrations close to the flammability limit. The analysis, which employs seven elementary reactions for the chemistry description, uses the ratio of the characteristic radical and fuel concentrations as a small asymptotic parameter, enabling an accurate analytic expression for the resulting burning rate to be derived. The analysis reveals that the steady-state assumption for chemical intermediaries, applicable on the hot side of the reactive layer, fails, however, as the crossover temperature is approached, providing a nonnegligible higher-order correction to the burning rate. The results can be useful, for instance, in future investigations of hydrogen deflagration instabilities near the lean flammability limit.