Numerical Study of Thermal-Diffusive Instability of Premixed Flames

Abstract

The 2-D thennal-diffusive model of premixed flames is solved numerically. The growth rates of the thermal-diffusive instability are compared to the linear theory. It is shown that the discrepancy, although large (a relative error than can be larger than 100%), behaves like O(I/β) as expected by asymptotics (β being the reduced activation energy or Zeldovich number). We additionally present results far in the non-linear domain. They exhibit turbulent behaviour which are qualitatively similar to the dynamical properties of the Kuramoto-Sivashinsky model-equation.

Key words:

• thermal-diffusive instability
• wrinkled premixed flame
• turbulent flame
• numerical combustion