Soot and Aromatic Species in Non-premixed and Partially-premixed Laminar Co-flow Flames

摘要

A joint AFRL-industry-university research team is studying the effects of alternative fuels on production of air pollutants in gas turbine engines. This paper will report on one portion of the overall research effort, in which PAH and soot are being studied in non-premixed flames and partially premixed laminar co-flow flames. A system for producing co-flow laminar flames with liquid hydrocarbon fuels was developed as part of this work. Results are reported for a fuel consisting of n-dodecane (75vol%) and m-xylene (25vol%) for a nitrogen-diluted non-premixed flame and a phi=6 partially premixed flame. Laser extinction was used to obtain the soot volume fractions and laser-induced fluorescence was used to detect two classes of aromatic species, 1 or 2 rings and 3 or more rings. Results from simulation of the flames performed by Innovative Scientific Solutions, Inc. using the UNICORN code are also presented. The peak soot levels measured in the experiments are almost three times the values obtained in computational results. The peaks of aromatic species in the computational results occur higher in the flames than in the experiments.