Effect of the mixture initial temperature on the velocity field in the swirling flame

Abstract

Abstract The paper presents the results of an experimental study of the flow structure of a turbulent swirling flame of a methane-air and syngas-air mixture at elevated temperature using modern optical methods PIV (Particle Image Velocimetry) and PLIF (Planar Laser-Induced Fluorescence). A comparison of the averaged flow characteristics of a high-swirl flame with an equivalence ratio Φ = 0.45 for syngas-air and Φ = 0.7 for methane-air mixture are performed with preheating the mixture to a temperature of 300, 400 and 500 K. The distribution of the fluorescence signal showed that the longitudinal size of the region of hot combustion products decreases significantly with increasing temperature of the mixture for both syngas-air and methane-air flames. For the flame of a mixture of methane-air and syngas-air heated to a temperature of 500 K, the size of the recirculation zone and velocity pulsation distribution are very similar, in contrast to a methane flame at lower preheating temperatures of the mixture.