Modeling the Response of Premixed Flame Transfer Functions - Key Elements and Experimental Proofs

Abstract

A wide variety of analytical models has been proposed to describe the transfer function of premixed flames submitted to flow disturbances. These models generally rely on a kinematic description of the flame reaction surface which is perturbed around its steady state. The response then depends on the type of flow perturbation considered, the mean flow characteristics and flame properties. Systematic comparisons between model predictions and experimental results are however less numerous. This study revisits some of these theoretical descriptions and their underlying hypotheses to delineate their domain of application. The main features of the response of premixed flames to flow disturbances are highlighted. Different mechanisms are identified and their analytical representation is discussed. It is shown that experimental observations provide useful guidelines in the flame transfer function modeling. The cases investigated include laminar and turbulent configurations in conical or inverted V-flame configurations. Effects of swirl, flame root dynamics and confinement are emphasized.