Distinct element modelling of non-spherical frictionless particle flow

The Discrete Element Method (DEM) is becoming widely used to simulate particle flows. It is a versatile and powerful tool. Its main limitation, the CPU time required, is becoming less critical with the development of computer technology. Most DEM simulations consider spherical particles in three dimension (3D) or circles in 2D. Several researchers are developing models of non-circular particles in 2D, but there are few applications of DEM to non-spherical particles in 3D granular flow. This paper proposes a technique of sphere intersection for particle description that is applied here in 2D and 3D. It then describes a known technique of sphero-cylinders in 3D and applies it to small-scale simulations of discharge of frictionless particles, modelling contact normal forces, from a hopper. Aspect ratio for these particles is shown to have a negligible effect on discharge rate. Simulations in 2D showed that the disc-shaped particles discharged 40% faster than the circular particles. Program code tests are described to check the complex model of rotational dynamics for non-spherical particles in 3D.

[1]  R. Nedderman Statics and Kinematics of Granular Materials: Euler's equation and rates of strain , 1992 .

[2]  Hans J. Herrmann,et al.  Discrete element simulations of dense packings and heaps made of spherical and non-spherical particles , 2000 .

[3]  Paul W. Cleary,et al.  DEM modelling of industrial granular flows: 3D case studies and the effect of particle shape on hopper discharge , 2002 .

[4]  Julio M. Ottino,et al.  Computational studies of granular mixing , 2000 .

[5]  P. A. Langston,et al.  Discrete element simulation of granular flow in 2D and 3D hoppers: Dependence of discharge rate and wall stress on particle interactions , 1995 .

[6]  Paul Langston,et al.  Integration schemes and damping algorithms in distinct element models , 2004 .

[7]  Paul W. Cleary,et al.  Centrifugal mill charge motion and power draw: comparison of DEM predictions with experiment , 2000 .

[8]  Colin Thornton,et al.  Impact of elastic spheres with and without adhesion , 1991 .

[9]  B.P.B. Hoomans,et al.  Granular dynamics simulation of segregation phenomena in bubbling gas-fluidised beds , 2000 .

[10]  Bernhard Peters,et al.  An approach to simulate the motion of spherical and non-spherical fuel particles in combustion chambers , 2001 .

[11]  A. J. Matchett,et al.  Vibrating powder beds: a comparison of experimental and Distinct Element Method simulated data , 2000 .

[12]  L. Vu-Quoc,et al.  A 3-D discrete-element method for dry granular flows of ellipsoidal particles , 2000 .

[13]  Paul Langston,et al.  Validation tests on a distinct element model of vibrating cohesive particle systems , 2002 .

[14]  J. M. Rotter,et al.  Visualisation of solids flow in a full scale silo , 1995 .

[15]  Alexander V. Potapov,et al.  The breakage induced by a single grinding ball dropped onto a randomly packed particle bed , 2000 .

[16]  Daan Frenkel,et al.  Molecular dynamics simulation using hard particles , 1989 .

[17]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[18]  Daniel Kleppner,et al.  An introduction to mechanics , 2010 .

[19]  Amlan Datta,et al.  Discrete element analysis of tumbling mills , 2000 .

[20]  G. A. Kohring,et al.  Computer simulations of critical, non-stationary granular flow through a hopper , 1995 .

[21]  Masao Sakamoto,et al.  Quasi-three-dimensional numerical simulation of spouted beds in cylinder , 2000 .

[22]  Shinichi Yuu,et al.  Numerical simulation for blockage of cohesive particles in a hopper using the distinct element method and its correlation with experimental results of real cohesive granular materials , 1998 .