Dynamic response of a ducted laminar premixed flame, part I: low amplitude forcing

Abstract

This paper presents an experimental study of the dynamics of a ducted, conical, laminar premixed flame subjected to low amplitude, acoustic excitation. The heat release response of the flame to velocity disturbances is investigated through measurement of the so called ‘flame transfer function’ for a wide range of forcing frequencies. The results agree well with those predicted by existing linear kinematic theories. The level of agreement, particularly in phase, for some of the experimental conditions appeared to be higher than any other previously reported validation of these theories. In keepingwith others, high speed photography of the flame clearly shows that the flame response includes waves on the flame front which are formed at the base and then convect along the flame.</p