Measurement of mixing processes with combined digital particle image velocimetry and planar laser induced fluorescence

A combined digital particle image velocimetry (DPIV) and planar laser induced fluorescence (PLIF) approach was developed to measure both the time mean and turbulent mass transport in mixing processes. The system couples the two well-known techniques to enable synchronized planar measurements of flow velocities and concentrations in a study area. The potential interference effect between the seeding particles for DPIV and the fluorescent dye excitation for PLIF was carefully investigated. The performance of the system was verified with the experimental results of a turbulent round jet discharging into a stagnant environment. Comparison between the measurements obtained in the present study with the large body of existing information on pure jets is satisfactory. The key advantage of the shorter duration required with this approach compared to point-based techniques is highlighted.