Temperature and species concentration measurements in a swirl-stabilized combustor

An experimental evaluation of a swirl-stabilized combustor is presented. The combustor is composed of two confined, concentric, swirling jets. The inner jet flow is lean premixed methane and air; the outer flow is air. Combustion is stabilized on a swirl-induced recirculation zone. Mean temperature and mean concentrations of major species are measured throughout the combustor, including the recirculation zone. Fine wire thermocouples are used to measure temperature. A gas chromatograph and a chemi-luminescence analyzer are employed to analyze samples extracted by a water-cooled gas-sampling probe. Results are presented in the form of isotherms and isopleths of species concentration in the combustor for two swirl conditions: co-swirl and counter-swirl. The effects of swirl on the combustion are discussed in light of flame quenching due to rapid dilution and cooling of the reacting inner jet flow by mixing with the outer flow. Evidence for probe induced perturbations of the combustion process is observed.