Applications of planar laser induced fluorescence in turbulent reacting flows

The basic principles of laser induced fluorescence are described with progressive presentation of simple and multi-level interaction schemas providing the relationship between the fluorescence signal and the local concentration of the investigated species in the laser field. Essential differences between laser induced fluorescence and flame chemiluminescence emissions are given. Techniques for imaging in the planar LIF configuration and procedures for calibration of the fluorescence intensity in absolute concentration values are described. Then, examples of imaging applications are given for instantaneous mapping of OH, CH, O 2 and temperature fields in turbulent reacting flows. In spite of uncertainties mainly due to collisional quenching effects, these imaging experiments are useful to interpret the interaction processes involved in turbulent combustion especially when several quantities can be simultaneously or conditionally registered.