Fuel Oxygen Effects on Soot Formation in Counterflow Diffusion Flames

Chemical effects of hydrogen addition on soot formation in counterflow diffusion flames: Dependence on fuel type and oxidizer composition

“…We used the higher value of XO in methane flames to achieve a moderately sooting flame for accurate SVF quantification. Similar strategies were used by Glassman and coworkers when they were studying fuels with significantly different sooting tendencies [32]. The nozzle exit velocities for all cases were maintained at V = 13.5 cm/s.…”

“…The radial velocity profiles at the nozzle exit may differ significantly from the frequently assumed parabolic profile [30] owing to nozzle heating [31] and buoyancy effects, adding additional complexity to the specifications of boundary conditions. Small amounts of oxidizer can be entrained on the fuel side of coflow flames through the stabilizing quenching zone at the flame's base (due to excessive heat and radical losses to the nozzle) [32]. These complications, together with the multi-dimensional nature make detailed kinetic analysis of the chemical effect of H2 addition in coflow flames unnecessarily challenging.…”

Synergistic effect on soot formation in counterflow diffusion flames of ethylene–propane mixtures with benzene addition

“…Fuel structure plays an important role in the formation and growth of PAHs and soot [5][6][7][8][9] because the concentrations of certain species, which can activate reactions related to PAH and soot, are highly dependent on fuel structure. Especially, the role of acetylene (C 2 H 2 ), which maintains a relatively high concentration in the high-temperature region, has been emphasized through the sequential pathway of H-abstraction-C 2 H 2 -addition (HACA) reactions [10][11][12][13].…”

Field measurements of soot volume fractions in laminar partially premixed coflow ethylene/air flames

“…Although soot formation in partially premixed flames (PPFs) has not been as extensively investigated as that in nonpremixed or premixed flames, a few investigations have characterized the effect of partial premixing on soot formation [24][25][26][27][28][29][30][31][32][33][34]. Much of this work is qualitative and employs global criteria, such as the mass of soot emitted [24,25,27] or smoke height [28], to characterize the effects of partial premixing.…”