Time-resolved particle image velocimetry in confined bluff-body burner flames
Résumé
Time-resolved particle image velocimetry was applied to a non-premixed turbulent flame generated by a confined bluff-body burner. Original synchronization of the experimental setup allowed us to obtain sequences of consecutive instantaneous velocity fields. Experimental limitations of the application of PIV in industrial-like burners are pointed out, requiring the development of specific preprocessing of the particle images associated with an original iterative procedure for cross-correlation calculation. Temporal evolution of coherent structures in the recirculation zone generated by the wake effect of the bluff body is visualized on sequences of consecutive velocity fields. Characterization of the temporal evolution of the stagnation points encountered in the recirculation zone reveals low-frequency movements of their axial locations.