Particle Tracking Velocimetry: A Review

Abstract

Particle tracking velocimetry (PTV) and particle image velocimetry (PIV) are methodologies that allow for volumetric velocity measurements within a fluid flow by imaging the motion of suspended micron-size particles. The only difference between the techniques is that PTV tracks the motion of individual particles, while PIV measures the mean displacement of groups of particles. PIV is more commonly used that PTV, and thus the techniques are robust and have been reviewed extensively. PTV, however, offers the advantages of increased spatial resolution and decreased computational cost. The focus of this review is to present the work that has been done to improve PTV. The review begins with an overview of the equipment required for a PTV experiment. Then, data processing algorithms are discussed for identifying particle images, mapping images to physical space, and tracking particles through time. Finally, post-processing techniques, which are used for calculating vorticity and pressure fields, are presented.