STRUCTURE AND DYNAMICS OF KINK AND CELLULAR FLAMES STABILIZED ON A ROTATING BURNER

We describe the formation and evolution of spatiotemporal patterns in cylindrical premixed flames stabilized on a rotating cylindrical burne r. We consider flames in the cellular regime, Le < 1, where the Lewis number Le is the ratio of thermal to mass diffusivity of a deficient c omponent of the combustible mixture. For the parameter regime consider ed burner rotation tends to be stabilizing in that increasing the rota tion rate generally promotes the development of traveling waves (TWs) from modulated traveling waves (MTWs). However, more complex dynamics occurs at the terminus of each of the TW branches. We find a number of unsteady, nonaxisymmetric modes of combustion, including (i) kink mod es, where one or more kinks (characterized by a jump or discontinuity in the distance from the flame to the burner) rotate around the burner , (ii) cellular flames in which one or more cells rotate around the bu rner (iii) Pacman modes, in which a rapidly rotating kink periodically overtakes and destroys more slowly rotating cells, with new cells cre ated elsewhere, (iv) two front modes in which the flame, though govern ed by a 1-step reaction mechanism, exhibits two distinct regions of bu rning in a localized region of space, and (v) double fire rotating cel lular flames (DF modes) which are MTWs where the modulation of each ce ll exhibits two maxima over each period such that one cell attains its first maximum simultaneously with the second maximum of its neighbor. Certain of the modes that we describe have not been previously observ ed for nonrotating burners either in experiment or in prior computatio n.