Influence of Multi-Source Vortex Structure on the Mixing of Fuel/Air

With the multi-source vortex (MSV) structure fixed on the exit plane of axial swirler, the flow field of combustor was simulated and the effect of MSV structure on the mixing enhancement of fuel/air was studied. The total temperature of the air inlet was 294.3K, ethane (C₂H₆) was used as the fuel and the total equivalence ratio was 0.6. The results indicated that a pair of small scale counter-rotating streamwise vortices was produced downstreams of each tab which enhanced the local mixing between fuel and air. For combustor with MSV, the distribution of fuel concentration was much more uniform than that without MSV. The mixing non-uniformity was decreased remarkably from 13.0% for a combustor without MSV to less than 7.6% with MSV. If the total blockage ratio was unchanged and two tabs were fixed on each swirl vane, the mixing non-uniformity would reach the smallest value and the mixing would be the best. If the number and shape of tabs were unchanged and the total blockage ratio of tabs was increased from 2.64% to 5.28%, the mixing non-uniformity would decrease from 7.6% to 6.5%, indicating a mixing enhancement of fuel/air.