Premixed Flame Propagation in the Flamelet Regime

Northwestern University, Evanston IL

Investigators

Abstract

The objective of this research in to understand complex flame-flow interactions that occur in laminar flames but have direct implications to premixed turbulent combustion, particularly in the flamelet regime. Models simulating these systems are investigated using both asymptotic techniques and numerical methods. In this work, two problems are considered. In the first, the structure, dynamics, and extinction of premixed edge flames in mixtures containing gradients of temperature or concentration are investigated. Because enthalpy variations affect the flame temperature and hence the rates of thermally sensitive chemical reactions, they influence fuel consumption, flame quenching, and emission of chemical pollutants; effects due to Lewis number, stoichiometry, and thermal expansion are also examined. The second issue concerns flame propagation in Poiseuille flow in which flame propagation depends on the intensity and scale of the underlying flow field. Total burning rate, flame shape, and propagation speed are parameters of interest, especially under conditions in which flashback is suppressed in the absence or presence of heat losses.