Investigation of Disk-Stabilized Propane Flames Operated under Stratified and Vitiated Inlet Mixture Conditions

Abstract

The work describes an experimental investigation of propane flames established through fuel injection and gradual premixing with preheated and vitiated oxidizing air, within a double-cavity arrangement, formed along a cylinder and two concentric disks. Ignition of the inlet stratified and vitiated mixture and flame stabilization is established at the recirculation region of the afterbody disk. Measurements of mean velocities, temperatures, OH* and CH* chemiluminescence and gas analysis provided information for the interpretation of the relative variations in flame structure and burner performance. The study illustrates some aspects regarding the influence of the preheated/vitiated conditions on the combustion of the inlet stratified fuel-air mixture profile, with respect to flame front stabilization, disposition, and burner emissions. Some important differences in the vitiated flame structure and topology are discussed in comparison to the unvitiated case characteristics, in an initial effort to establish the possible advantages or disadvantages of incorporating preheat and vitiation in stratified operation.