Figure 1:  Instantaneous 3D fame structure in (a) air, and (b) oxy-fuel atmospheres. The iso-surface of T̃=1280K is colored with Y_H2O, the particles are colored to indicate Y_vol (= 0 in most regions), and the wall is colored to indicate the temperature. The inset shows a magnified ed view of the quarl zone, and the unburnt particles (Y_vol >0) crossing the quarl zone are indicated. The green horizontal lines in (a) indicate the sample lines where the velocity components are measured.