Effect of Sub-Atmospheric Pressure on Soot and Hydroxyl Concentrations in Quenched, Premixed Ethane/Air Flat Flames

Abstract

Experiments have been designed and executed to answer the following specific questions about the role of hydroxyl and pressure in the formation/destruction mechanism for combustiongenerated soot: (a) what effect, if any, does sub-atmospheric pressure have on the stoichiometry for the onset of soot; (b) is there really a limiting pressure below which soot fails to form, even though the flame was sooting at a higher pressure; and (c) if the limiting pressure does exist, is there any correlation between the disappearance of soot and the hydroxyl radical concentration as a function of pressure? From measurements on quenched, premixed flat ethane/air flames, which are the first of their kind, the answers of these questions were learned to be none, yes, and yes, respectively.