Hydrodynamic and thermodiffusive instability effects on the evolution of laminar planar lean premixed hydrogen flames

C. Altantzis, C. E. Frouzakis, A. G. Tomboulides, M. Matalon, K. Boulouchos

Research output: Contribution to journalArticle

Abstract

Numerical simulations with single-step chemistry and detailed transport are used to study premixed hydrogen/air flames in two-dimensional channel-like domains with periodic boundary conditions along the horizontal boundaries as a function of the domain height. Both unity Lewis number, where only hydrodynamic instability appears, and subunity Lewis number, where the flame propagation is strongly affected by the combined effect of hydrodynamic and thermodiffusive instabilities are considered. The simulations aim at studying the initial linear growth of perturbations superimposed on the planar flame front as well as the long-term nonlinear evolution. The dispersion relation between the growth rate and the wavelength of the perturbation characterizing the linear regime is extracted from the simulations and compared with linear stability theory. The dynamics observed during the nonlinear evolution depend strongly on the domain size and on the Lewis number. As predicted by the theory, unity Lewis number flames are found to form a single cusp structure which propagates unchanged with constant speed. The long-term dynamics of the subunity Lewis number flames include steady cell propagation, lateral flame movement, oscillations and regular as well as chaotic cell splitting and merging.

Original languageEnglish (US)
Pages (from-to)329-361
Number of pages33
JournalJournal of Fluid Mechanics
Volume700
DOIs
StatePublished - Jun 10 2012

Keywords

  • combustion
  • flames
  • instability
  • laminar reacting flows

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Hydrodynamic and thermodiffusive instability effects on the evolution of laminar planar lean premixed hydrogen flames'. Together they form a unique fingerprint.

Cite this