DEM study of granular flow characteristics in the active and passive regions of a three‐dimensional rotating drum

Abstract

Three-dimensional modeling of the solid motion in a lab-scale rotating drum has been conducted via the discrete element method. After validating the simulated results with available experimental data, the active-passive interface was identified, following which particle-scale information in these two regions, in particular the influences of fill level and rotating velocity, were obtained. The results demonstrate that: (1) the total number of particles in the passive region is three times that in the active, (2) the transverse and axial velocities span a wider range in the active region, with the transverse values being greater, (3) the collision force is much higher in the active region, with the greatest magnitudes in the y direction relative to that in the x and z directions, (4) particle displacements are generally lower and have a narrower distribution in the active region, (5) the local solid residence time (SRT) distribution profiles are similar axially in that the highest SRT magnitudes are at the center region of the bed, while the other parts of the bed have uniform SRT magnitudes.

Segregation behavior of binary mixtures of cylindrical particles with different length ratios in the rotating drum

“…The validation is carried out with the experimental results of Alizadeh et al Important parameters (namely, dynamic angle of repose, streamwise velocity, and active layer thickness) characterizing the rolling regime obtained numerically show a quantitative agreement with the experimental measurements reported . Details can be found in our previous work . Based on this validation, the DEM platform is extended to explore the granular flow of superquadric particles.…”

“…For the soft‐sphere collision model adopted to describe the collision behavior, in addition to the basic material information (e.g., density, diameter), other important properties (e.g., Young's modulus, Poisson ratio, restitution coefficient) of the granular material are provided in Table . The choice of these parameters is based on the previous work conducted for monodisperse spherical particles, which has been well‐validated with experimental results …”

Rheology and scaling behavior of cascading granular flows in rotating drums

“…The cascading and cataracting regimes provide suitable operational conditions for industrial mills and granulators 21,24 . In particular, the active flowing layer thickness is an important quantity for mixing, grinding, thermal and convection properties 19,20,[25][26][27][28][29][30] . Nevertheless, these regimes remain poorly understood.…”

Screw‐generated forces in granular media: Experimental, computational, and analytical comparison

“…Studies examining the comparisons between DEM simulations and granular media experiments mainly focus on either of the following two aspects: the flow patterns of the granular material or the generated reaction forces of a variety of machines. Much of the literature focuses on the tumbling and mixing patterns of drums or other rotating items . Others study blending and mixing machines.…”