Effect of Additives on Diesel Spray Flames in a Controllable Active Thermo-Atmosphere

The active components, such as OH and their concentrations in the coflow, have a strong effect on the combustion process of diesel fuel spray flames in the Controllable Active Thermo-Atmosphere (CATA), which then will affect the soot incandescence of the spray flames. CO₂ and H₂O₂, the additives which have contrary effect on the concentration of the active components, were mixed separately into the thermo-atmosphere before the jet spray were issued into the coflow, which changed the boundary condition around the central jet and influenced the combustion characteristics and soot incandescence.

The combustion characteristics such as ignition delay and flame liftoff height of the central spray flames are measured and the linkage between these two parameters is investigated at different coflow temperatures. The effect of additives concentration on ignition delay, liftoff height and soot incandescence are studied and then the relationship of soot incandescence and flame liftoff height is concluded and shows the strong dependence of soot incandescence on flame liftoff height.