Investigation of the Structure of a Laminar Non-Premixed Flame in an Unsteady Vortical Flow.

摘要

Although organized vortical motions have been observed in a variety of turbulent flames, there have been only a few experimental studies which have directly examined the structure of a flame imbedded in an unsteady vortical flow. In the present work, this problem is investigated using a laminar co-flowing jet flame in which a periodic vortical motion is induced by acoustic excitation of the fuel stream. A variety of optical planar imaging techniques are employed to define the instantaneous flame structure. Particle tracking is used to obtain the instantaneous two-dimensional velocity field. These measurements are combined to follow the evolution of the flame in the unsteady velocity field over one cycle of the excitation. Keywords: Combustion, Reacting flows, Turbulent mixing, Diagnostics, Particle tracking, Flow topology. (EMK)