Eccentric flows registered by DPIV in a model of silo

Abstract

The paper presents results of eccentric flows of amaranth and flaxseed in a flat-bottomed Plexiglas model of silo. The images of the flowing grains were registered by a camera of high resolution. The Digital Particle Image Velocimetry technique was used to analyse the seed flow. For this purpose long sequences of digital images of the flowing grains were processed to obtain full velocity vector fields as well as selected velocity profiles for the analysed discharge processes. Deformations occurred in the flowing material are also evaluated. The experiments were made in the model of three different roughness of the walls, the smooth and lined with sand paper of two different roughness. To investigate effects of eccentricity, both during filling and discharge, the model was filled centrally at the symmetry axis, close to the left edge of the silo, and near its right edge. The filling pipe was also located centrally or eccentrically above the model. The differences between different modes of flow are described and analysed in detail. © 2007 Springer.