Plasma assisted combustion: Dynamics and chemistry

Counterflow diffusion flames

Soot formation in laminar counterflow flames

The effect of electric fields on the burning velocity of various flames

An experimental study has been made of the structure and the blow-off mechanism of the laminar counterflow diffusion flame established in the forward stagnation region of a porous cylinder. Concentration profiles of the stable species were determined using a microprobe sampling technique and gas-chromatographic analysis for hydrocarbon flames at atmospheric pressure. The over-all structure of the flame was examined by optical interferometry. Experimental results show that there are always various intermediate hydrocarbons and some oxygen on the fuel side of the flame. Hydrogen and carbon monoxide, which are the intermediate products, exist on both the fuel and air sides of the flame. The maximum concentrations of hydrogen and various intermediate hydrocarbons are found near the stagnation point of the counterflow. Although the flame approaches the cylinder surface when the fuel-ejection rate is decreased or the stagnation velocity gradient is increased, the differences in the concentration profiles for the case of a low fuel-ejection rate and for the case of a large stagnation velocity gradient are remarkable. It has been confirmed that critical blow-off of the flame is due to chemical limitations on the combustion rate in the flame zone and is clearly distinguished from blow-off caused by thermal quenching of the flame.

Philip M. Becker

Papers

A mathematical model of the opposed-jet diffusion flame: Effect of an electric field on concentration and temperature profiles

The effects of an electric field on an opposed-jet diffusion flame

Effect of electric fields on ducted diffusion flames

En 28f – the effect of electric fields on nitrogen dioxide in flames: les effets des champs electriques sur le bioxyde d'azote dans les flammes