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 induc ed fluorescence (PLIF) approach was developed to measure both the time mean and turbulent mass transport in mixing processes. The system couples the t wo 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 excit ation for PLIF was carefully investigated. The performance of the system wa s verified with the experimental results of a turbulent round jet dischargi ng into a stagnant environment. Comparison between the measurements obtaine d in the present study with the large body of existing information on pure jets is satisfactory. The key advantage of the shorter duration required wi th this approach compared to point-based techniques is highlighted. (C) 200 0 Elsevier Science Inc. All rights reserved.