Irregular plastic particles settling in non-quiescent water

A new method for tracking both the velocity and the orientation of irregular particles that settle in water is tested for several plastic particles. The method uses a stereoscopic setup with two cameras and uses background illumination to create shadow images of the particles. The particle three-dimensional shape has been found in a separate scanning. Artificial shadow images are generated as a function of position and orientation. This is used in a optimization process to estimate the physical position and orientation. An experimental setup was developed to test both quiescent and turbulent conditions. Different particles have different settling models with motions that involve rotation or oscillation of the particles. Measurements on a small sample (six particles) indicate that while many particles were relatively unsensitive to turbulence, some particles have settling modes that are significantly influenced by turbulence.