Hydrocarbon species concentration measurements in diluted laminar jet diffusion flames from 1 to 8 atmospheres

摘要

Hydrocarbon species concentrations were measured along the centerline of a laminar jet diffusion flame from one to eight atmospheres. The objective was to better understand soot production and oxidation which will ultimately help reduce soot emissions from engines. The ethylene-air flames were diluted 80% by volume with either carbon dioxide or helium to reduce soot loading and allow sample extraction. The fuel-to-air velocity ratio was set to unity for all cases, i.e., air co-flow had the same exit velocity as the reactant mixture (fuel and diluent), to minimize shear-layer induced entrainment and the fuel mass flux was held constant for all pressures. As expected, concentration of C_2H_2 and C_6H_6 were much higher in the helium-diluted flames, corresponding to higher soot yield, compared to the CO_2-diluted flames.