Analytical study in the mechanism of flame movement in horizontal tubes
arXiv:1109.0495 · doi:10.1063/1.3684712
Abstract
The problem of premixed flame propagation in wide horizontal tubes is revisited. Employing the on-shell description of flames with arbitrary gas expansion, a nonlinear second-order differential equation for the front position of steady flame is derived. Solutions to this equation, obtained numerically, reveal two distinct physical regimes of laminar flame propagation controlled by the strong baroclinic effect. They differ by the front shape and flame speed, the ratio of the total consumption rates in the two regimes being 1.4 to 1.8, depending on the value of the gas expansion coefficient. Comparison with the existing experimental data on methane-air flames is made, and explanation of the main trends in the observed flame behavior is given. It is shown, in particular, that the faster (slower) regime of combustion is realized in mixtures close to (far from) the stoichiometric composition, with pronounced changeover in between.
20 pages, 13 figures
References in corpus (1)
Cited by in corpus (4)
- Premixed flame propagation in vertical tubes
- Analytical study in the mechanism of flame movement in horizontal tubes. II. Flame acceleration in smooth open tubes
- Numerical study of strongly-nonlinear regimes of steady premixed flame propagation. The effect of thermal gas expansion and finite-front-thickness effects
- Effect of vorticity flip-over on the premixed flame structure: First experimental observation of type I inflection flames