Velocity fields of nonpremixed bluff-body stabilized flames

The velocity fields of nonpremixed circular-disk stabilized flames are meas ured by a two-component laser Doppler velocimeter. The results are presente d in different flow regimes: prepenetration, penetration, and large shear f low. The velocity-vector fields, streamline patterns, corresponding flame a ppearances,and axial length of recirculation bubble in different flow regim es are illustrated and compared. mean velocity and turbulent stresses along the central axis are presented and discussed. The combustion characteristi cs in different characteristic flow regimes are presented through the discu ssion of entrainment, diffusion mixing capabilities, flow patterns, and tur bulence properties. The detached flames, particularly operating in the tran sition flow regime, offer a relatively efficient combustion situation. Oper ating the concentric-jets burner in the regime of high shear flow do not be nefit mixing and flame stability through the bluff-body effect. [S0195-0738 (00)00102-3].