Effects of Nozzle Orientation on the Structure and Emissions of Spray Flames

Abstract

An experimental study of the effects of the orientation of the liquid fuel stream relative to the air stream from a twin fluid atomizer located in an open-jet wind tunnel is presented. The orientation angle was set at 0 (concurrent), 45, 90, 135, and 180 deg (directly opposed). At 45 and 90 deg, the flame length, the radiation emission, and the concentrations of carbon monoxide, carbon dioxide, nitric oxide, and soot are higher than those at co-flow conditions. At 135 deg, all these quantities decrease markedly from their values at 90 deg and again increase when the fuel and air streams are directly opposed (180 deg). These changes are discussed in terms of the influx of air and recirculation of combustion products into the salient zones of the flame.