Air/fuel mixing in jet flames

The paper examines eight diverse regimes in which fuels can mix and react with air. These comprise: (i) Lifted subsonic; (ii) supersonic jet flames, (iii) without (iv) cross flows; (v) Rim-attached flames; (vi) Early Downwash (vii) Downwash-attached (viii) Fire Whirls. Correlations of characteristics within these are principally terms a dimensionless Flow Number, U*, Cross Reynolds number, Rec, and, for Whirls, Critical Velocity, CV. Boundaries seven the identified, through plots against eighth plot CV U*. circumstances transitions between identified. study involves variety CH4 flow flame measurements, wind tunnel. flows initially create small lee-side downwash, due to depression pressure. With increasing fuel this might extend 1.3 m downwards from horizontal tip vertical burner. Jet flames attach become significant above Rec ≈ 2000. More extensive downwash further delay blow-off. Regime boundaries constructed on U*/Rec diagram covering lifted early downwash-attached flames. most powerful tend be lifted, choked, flow, fire whirls. Combustion becomes less efficient at high low although was efficiently reacted. Experimental values ratio air velocity, u/uc, ranged about 10 30 0.3 3.6, blow-off, rim-attached latter comprise an important category, often intermediate