This paper reports measurements of droplet characteristics and flow field in a spray flame
with inner and outer swirling air streams. The spatial distribution of droplet characteristics
produced by the burner's airblast atomizer was measured using dual-phase Doppler
anemometry (PDA). The spray flame was operated near the lean blow-out limit at two flow
conditions: co-swirling (flow rotation in the same direction) and counter-swirling (flow
rotation in opposite directions). In both cases, the flame exhibited a U-shaped form and was …