FUEL COMPOSITION EFFECTS ON THE VELOCITY FIELD IN A LEAN PREMIXED SWIRL-STABILIZED COMBUSTOR

摘要

Fuel composition effects on the flow-field of a lean premixed swirl-stabilized burner were studied. Methane (CH_4) was enriched with hydrogen (H_2) to vary the fuel composition. The burner inlet had 28-degree swirl vanes located in the annulus around a centerbody. Combustion occurred in an air-cooled quartz chamber at atmospheric pressure. The measurements were obtained, using the particle image velocimetry (PIV) technique, which allowed the 2-D velocity and vorticity fields to be examined for different fuels. The average velocity field was significantly altered, including the shape of the central and corner recirculation zones in the H_2 enriched flames. The instantaneous velocity fields showed corresponding differences as well. The length scales and vorticity levels of the time-averaged velocity field differed from those for the instantaneous fields, indicating the importance of temporally resolved measurements.