Hydrogen addition to acetylene–air laminar diffusion flames: Studies on soot formation under different flow arrangements

Effects of hydrogen addition on soot formation and oxidation in laminar premixed C 2 H 2 /air flames

“…Due to these factors that can also affect soot formation and oxidation during engine operation, the effect of hydrogen blending into gasoline and diesel fuels on soot yield has not been clearly understood yet. In the previous experimental investigations using laminar diffusion flame geometry [6,9], the hydrogen addition as a fuel additive was found to efficiently suppress soot emissions through the following mechanisms: (1) a thermal effect due to changes in the flame temperature, (2) a dilution effect caused by changes in the amount of carbon per unit mass of fuel gas mixture, and (3) a direct chemically inhibiting effect. Among these mechanisms proposed, the chemically inhibiting effect of hydrogen addition on the soot formation is, however, least understood due to its complex nature of chemical kinetics coupled with preferential diffusion process (which causes the changes in free-stream fuel concentration and local hydrocarbon concentration [10]).…”

Role of Fluid-Dynamics in Soot Formation and Microstructure in Acetylene-Air Laminar Diffusion Flames

“…The thermophoretic sampling probe and thermocouple were mounted on a traverse assembly which can be moved both horizontally and vertically with the help of lead screws to facilitate collection of soot samples and temperature measurement at any location in the flame with reference to the burner exit plane. The experimental set-up, TEM image analysis and the calculation of soot characteristics procedure is described in detail in author's earlier work [18].…”

“…Interestingly, these authors reported the existence of an un-oxidized pool of CO and H 2 at the IDF tip [16]. The surface growth is the dominant mechanism in soot formation [17], in inverse diffusion flames surface growth is very small and therefore these flames produce less soot [18]. Among the listed publications, little work has been done on the inverse diffusion flame.…”

An experimental study on hydrogen–methane mixtured fuels

“…They reported that the model predictions were examined against experimental results of other investigators, and good agreement has been generally found for a wide range of initial conditions. In order to asses the benefits and possibilities of the addition of hydrogen for emissions reduction together with the variable air flow distribution between primary and secondary zone of combustion chamber, an experimental work has been carried out by Juste [8]. Safta and Madnia [9] investigated numerically the ignition dynamics and subsequent flame evolution of hydrogen-enriched methane mixtures in a reacting vortex ring configuration.…”