Abstract

Even after few decades of research, the study of particle motion taking place during silo discharging hasn’t been fully addressed, both experimentally and numerically, because of nontrivial behaviors that occur during associated flow patterns. For instance, discrete element method (DEM) has shown good qualitative prediction potential of velocity profile, but, on the other hand, frequently failed to match quantitatively experimental measurements, especially close to the outlet. This could have different reasons: bad choice of granular materials property, initial packing that does not fully agree with experimental conditions or the physical/mechanical laws assumed to govern the flow. The main scope of this paper is to compare experimental results with DEM simulations performed in the Yade framework, in the case where the sources of uncertainty during modeling have been reduced as much as possible. Particularly, initial packing of particles in silo discharging simulation has been obtained by image processing of X-Ray tomography imaging data to create a structural faithful model. All measurements have concerned different types of granular material, i.e. glass spheres, rice and sorghum mixed with tracer particles of similar physical properties but different shapes (i.e. glass grit, sorghum and rice, respectively). In that way, the comparison at different discharging times between DEM simulation and time-lapse X-ray tomography measurements can focus on evaluations of particle behaviors at the level of the closest neighborhood of tracer particles.

Authors (4)