2020 Volume 15 Issue 1 Pages 159-169
This paper presents experimental results of an unconstrained flow of dry sand down an inclined board at small scale, followed at the toe by a horizontal plane on which the sand spreads. The runout length increases with the increase in the volume of the falling sand and the slope angle. In order to identify these characteristics, mass point movement down an inclined board is introduced. If the position of the mass at start is given, it is possible to determine velocity and position of the point at any given time by means of the relationship of the energy loss, however, the mass point modeling, in which the mass point slides down the inclined board and reaches the horizontal plane, does not fully represent the runout length increase with the increase in the slope angle. To get better identification, we improve the mass-point modeling to explain climb-over and collision of particles, which may occur in the sand sliding down the slope.