| Quantitative fluid flow visualization and measurements are highly demanded in mechanical, chemical, medical and many other science and engineering fields to investigate fluid phenomena, understand theoretical principles and support computational prediction. Three-dimensional Particle Tracking Velocimetry (3D-PTV) is a powerful and comprehensive measurement technique that provides instantaneous 3D volumetric velocity information and Lagrangian description of particle trajectories. This work is based on the 3D-PTV technique that was developed at the Institute of Geodesy and Photogrammetric at the Swiss Federal Institute of Technology, Zurich. Theoretical principles of the technique were studied based on geometric imaging and computer vision. A complete 3D-PTV system was designed, assembled, synchronized, and tested. A study of the accuracy of the 3D-PTV system in terms of the influence of each component was performed. 2D-PIV (Particle Image Velocimetry) measurements were done on the same experimental setup used in the 3D-PTV system. Results showed good quantitative agreement between the velocity information obtained with the two systems, which validates the results of the 3D-PTV measurement system. The developed 3D PTV system was applied to the study of mixing in a stirred tank showing that this technique has great potential for the study of low Reynolds number flows where the time-resolved trajectory of particles is important. Further improvement on the configurations and data analysis of the system can provide higher accuracy, higher spatial and temporal resolution, and less complexity, which will lead to an extension on its application. |
