Post-processing of discrete flow field data for particle tracking velocimetry

To measure the surface flow in a physical river model, a brief introduction was given to the method of Particle Tracking Velocimetry (PTV). According to the characteristics of PTV by seeding particles on the water surface, particle images can be captured by CCD cameras and recognized by image division. PTV algorithm gives one vector for each particle based on the principle the trajectory of an individual particle is continuous. The key problem of analyzing the flow speed field accurately is post-processing of discrete flow field data. Errors of measurement discrete data are removed by the basic law of water movement. To attain the whole flow speed field, the methods of interpolation of discrete flow field data were proposed. In addition, the graphics of streamlines, velocity isolines and vortex isolines were drawn by the theory of hydraulic calculation.