PIV for granular flows

Particle image velocimetry (PIV) has been adapted for use in measuring particle displacement and velocity fields in granular flows. Seeding is achieved by using light and dark particles. The granular flow adjacent to a clear bounding wall is illuminated with a strobe, and the recorded images are analyzed using standard PIV techniques. The application is demonstrated by measuring convection rolls in a granular bed undergoing vertical oscillations. The PIV measured displacement is consistent with displacement of a marked layer of particles.