Cylindrical object contact detection for use in discrete element method simulations, Part II—Experimental validation


B. Hancock, C. Wassgren, J. Curtis, M. Kodam, R. Bharadwaj




Chemical Engineering Science



This article is the second of two focusing on cylindrical object contact detection. The first part presents algorithms for determining if contact occurs between a cylindrical object and a plane, and between two cylindrical objects, in addition to expressions for contact overlap, contact normal vector, and contact location. This article presents the tests and results used to quantitatively validate the algorithms implemented in three-dimensional discrete element method (DEM) simulations. In particular, four tests are performed. The first consists of a comparison against analytical expressions for post-collision translational and rotational velocities for a single cylinder impacting a flat wall. The second involves comparisons against experimental residence time measurements of a cylindrical particle moving within a baffled, rotating horizontal cylinder. The third test consists of comparisons against experimental bulk density measurements of cylindrical particles dropped into a cylindrical container. The last test compares experimental and computational values of the dynamic angle of repose in a rotating drum. In addition to true cylindrical objects, comparisons are also made in the first three tests against two cylindrical object approximations using glued spheres. The true cylinder model performs well in each of the tests while the glued sphere approximations perform poorly, especially when fewer spheres are used to represent the cylinder shape. These studies demonstrate that the cylinder contact algorithms presented in the first article perform correctly, and more accurately model real cylinder behavior than glued sphere approximations.


Contact detection, Cylinders, Discrete Element Method (DEM), Particle shape, Simulation, validation

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