A combination of simultaneous planar laser-induced fluorescence and particle image velocimetry measuring-technique is applied to investigate the flow field in a jet-in-crossflow arrangement. Two-dimensional maps of normalized averaged jet-concentrations <
>, axial turbulence intensities
andnormalized Reynolds-fluxes <
are measured. In these experiments, the influence of a swirl in the jet as well as varying turbulence levels characterized by the Reynolds number on the mixing efficiency is investigated. A direct relation between Reynolds-fluxes (and -stresses) and the increasing turbulent flows’ mass-transfer is observed.