Simultaneous high repetition rate PIV-LIF-measurements of CIVB driven flashback

Combustion induced vortex breakdown (CIVB) generating flame flashback in swirl burners was investigated experimentally. Since previous work identified the interaction of turbulence and chemistry as the root cause for CIVB, the particle imaging velocimetry and the laser induced fluorescence were chosen for the experimental investigation. Due to the high dynamics during flame flashback the transient behavior of the flame was analyzed with a high time resolution. The results of the experiments confirm the mechanism derived from the analysis of earlier CFD data. In addition, instantaneous data is provided, which explains the strongly stochastic fluctuation of the flame tip before CIVB driven flashback occurs. Finally conditioned PIV-PLIF data of the propagating flame during CIVB driven flashback show the occurrence of local flame quenching and the influence of the reaction on the flow during flashback.