A low cost system for the estimation of concentration and velocity profiles in rapid dry granular flows

A series of laboratory experiments with granular material has been carried out at the Hydraulic and Environmental Engineering Department of the University of Pavia (Italy). The aim was to investigate the internal properties of fast moving dry granular flows, with particular attention paid to the measurements of concentration and velocity profiles. A low-cost acquisition system was built using a Pulnix digital camera and off-the-shelf components and integrating only open-source software around a GNU/Linux operating system. Different techniques for the measurements of velocity and concentration profiles have been proposed and tested. The flow regimes have been investigated and a distinction between “front”, “body” and “tail” of the moving mass has been established in terms of the flow concentration. Additionally, a comparison with experimental results and theories found in the literature has been outlined.