Laser-induced breakdown spectroscopy in a partially premixed turbulent jet flame

A new approach for studying mixing and combustion phenomena in turbulent partially premixed flames using laser-induced breakdown spectroscopy (LIBS) is demonstrated. Setting the laser pulse energy just above the breakdown threshold in the cold gas allows statistical data to be obtained concerning the probability of finding cold or hot gas inside the measurement volume. Moreover, a compositional analysis utilizing the LIBS spectra allows the mixing of the different cold gas flows to be studied. A proof-of-concept experiment is carried out in a turbulent jet flame stabilized on a coaxial burner. The LIBS data agree well with results obtained by planar laser-induced fluorescence of OH radicals.