Motion of granular particles on the wall of a model silo and the associated wall vibrations

Dynamic phenomena during discharge of a silo are not well understood. This study uses a dual approach to quantify the motion of both the particulate solid at the wall of a model silo and the wall itself. The motion of particles was recorded visually using a digital CCD camera. The particles are seen to move with an intermittent motion. Image analysis techniques were then applied to obtain quantitative measurements of the particulate velocity. In relation to the particle motion, the silo walls were observed to vibrate during discharge. These vibrations were measured using a laser vibrometer to obtain independent measurements of the radial displacement and velocity. This enabled comparisons to be made between the particulate motion and the wall vibrations. Results are presented for barley and for polyethylene terephthalate pellets.