Abstract

Although unsteady flame quenching is a classical combustion problem, several key features of the process have yet to be understood. As an example, for an unsteadily propagating flame (away from the flammability limits) stagnating on a cold wall, there has not been conclusive experimental and theoretical agreement on the effects of varying the thermal boundary conditions on the flame extinction process. Characterization of the flame quenching problem is exacerbated by the length scales over which it occurs. The flame quenching distance for single sided flame quenching at atmospheric pressures is on the order of hundreds of micrometers, and thus few diagnostics can be used to determine the extent to which the flame propagates towards a specified temperature wall. The most meaningful diagnostics to date for such processes have been heat transfer measurements of the wall heat flux as the flame quenches. These diagnostics although second hand, provide information about the flame trajectory during a given quenching process. Even in the absence of detailed species description of the quenching process, several interesting features are noted as a result of the evolution of major species. The effect of water condensation during flame quenching which is examined in this study has been neglected in many studies of flame quenching. It is shown that coupling water condensation to the quenching process modifies both the extinction chemistry and also the wall heat flux measurement.

This content is only available via PDF.
You do not currently have access to this content.