GRAVITY FLOW OF GRANULAR-MATERIALS ROUND OBSTACLES .1. INVESTIGATION OF THE EFFECTS OF INSERTS ON FLOW PATTERNS INSIDE A SILO

Triangular and square inserts were placed at different heights within a tall observation bunker of rectangular cross-section. The flow patterns produced by the materials were photographed through the float glass front wall of the bunker. The photographs taken at different exposure times were used to determine particle streamlines, vertical velocity contours and the boundaries of the so-called stagnant zones formed inside the bunkers. Velocity contours within the converging flow zones were compared with the predictions based on the kinematic flow model proposed earlier by the authors. The results presented seem to indicate a dependence of the observed flow fields on the magnitude of particle velocities within the bunker.