Analysis of Highly CO2-Diluted Oxy-propane Flames Stabilized over a Multihole Burner of a Model Gas Turbine Combustor

Premixed oxy-propane flames are investigated numerically in a multihole model gas turbine combustor at various inlet mixture compositions over a range of equivalence ratios (0: 0.241-0.500), oxygen fractions (OF: 32.4-60.0%), and adiabatic flame temperatures (Tad: 1600-1900 K) at a constant bulk throat velocity of 5.2 m/s. The flames in multihole combustors are highly influenced by their corresponding adiabatic flame temperatures. Similar flame shapes are observed at constant Tad, where cases with (0 = 0.241, OF = 60%) and (0 = 0.50, OF = 32.4%) both represent lifted flames at Tad = 1600 K, anchored flames in (0 = 0.276, OF = 60%) and (0 = 0.50, OF = 36.6%) at Tad = 1750 K, and anchored stronger flames in cases (0 = 0.313, OF = 60%), (0 = 0.392, OF = 50%), and (0 = 0.50, OF = 40.8%) at Tad = 1900 K. Flames in a multihole combustor are characterized by the presence of an outer recirculation zone (ORZ) only. In comparison with a swirl stabilized combustor in identical inlet conditions, flames in a multihole combustor demonstrate a lower Damko''hler number (Da), higher flame thickness, elevated pattern factor, and increased CO emission. Due to the reduced vorticity level because of the absence of swirl motion, the multihole flames have higher axial temperature than the swirl-stabilized ones.

Automated summary

The characteristics of premixed oxy-propane flames in a multihole model gas turbine combustor are investigated numerically. The results show that the flame shape in the multihole combustor is highly influenced by the adiabatic flame temperature. Compared to a swirl stabilized combustor, the multihole combustor exhibits higher flame thickness, increased CO emission, and lower Damko'hler number.