S&T Project 24012 Final Report: Methodology Assessment for Large-Scale Particle Image Velocimetry

Large-Scale Particle Image Velocimetry (LSPIV) is a technique utilized by Reclamation and other entities to obtain surface velocity measurements both in field and laboratory settings. Results from this study indicate that both field and laboratory flow measurements required the addition of seeding material, even under turbulent conditions. Effective seeding materials included high-contrast, easily dispersible particles such as wood shavings, polystyrene spheres, and dark-colored water beads, all of which minimized clumping and enhanced particle visibility. Camera settings of 30 frames per second were sufficient for measuring velocities below 3 ft/s. For higher velocities, 60 or 120 frames per second are sufficient, with the goal of having a particle move approximately 2 pixels per frame. For current laboratory and field applications, PIVLab was identified as the preferred processing software, as TRiVIA was limited by its requirement for aerial video input. Future work should include the evaluation of Reclamation’s recently acquired LiDAR-compatible UAS system for LSPIV data collection, followed by a comparative assessment of available processing software.