Discrete element method study on hopper discharge behaviors of binary mixtures of nonspherical particles

AIChE Journal ◽  
2020 ◽  
Vol 66 (8) ◽  
Author(s):  
Ya Zhao ◽  
Jia Wei Chew
Keyword(s):  
Discrete Element Method ◽  
Binary Mixtures ◽  
Discrete Element ◽  
Nonspherical Particles ◽  
Hopper Discharge ◽  
Element Method

Experimental and Numerical Investigation on the Discharge of Wood Pellets From a Hopper With the Discrete Element Method

2012 ◽  
Author(s):  
Dominik Höhner ◽  
Siegmar Wirtz ◽  
Viktor Scherer
Keyword(s):  
Discrete Element Method ◽  
Bulk Density ◽  
Particle Shape ◽  
Discharge Rate ◽  
Discrete Element ◽  
Wall Friction ◽  
Approximation Schemes ◽  
Wood Pellets ◽  
Hopper Discharge ◽  
Element Method

In this study hopper discharge experiments with wood pellets were conducted. The experimental bulk density, flow behavior and discharge rate were compared to corresponding 3-dimensional discrete element simulations with both multi-sphere and polyhedral approximations of the pellet geometry. Additionally a numerical sensitivity analysis for the particle-wall friction was made in order to evaluate the influence of this parameter on hopper discharge in the context of different particle geometries. In the past comparisons of experimentally and numerically obtained results demonstrated the adequacy of the discrete element method for predicting the general discharge behavior of a hopper. Nevertheless, in this study, comparing two different particle shape-approximations, significant differences in terms of bulk density, discharge rate, flow profile and dependency on the particle-wall friction coefficient between both investigated particle-shape approximation schemes could be observed. As a result, particle shape-representation must be considered a significant parameter in DEM-simulations.

scholarly journals Discrete Element Method Investigation of Binary Granular Flows with Different Particle Shapes

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1841
Author(s):  
Yi Liu ◽  
Zhaosheng Yu ◽  
Jiecheng Yang ◽  
Carl Wassgren ◽  
Jennifer Sinclair Curtis ◽  
...  
Keyword(s):  
Discrete Element Method ◽  
Binary Mixtures ◽  
Particle Shape ◽  
Shear Flows ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Discrete Element ◽  
Particle Interactions ◽  
Particle Alignment ◽  
Element Method

The effects of particle shape differences on binary mixture shear flows are investigated using the Discrete Element Method (DEM). The binary mixtures consist of frictionless rods and disks, which have the same volume but significantly different shapes. In the shear flows, stacking structures of rods and disks are formed. The effects of the composition of the mixture on the stacking are examined. It is found that the number fraction of stacking particles is smaller for the mixtures than for the monodisperse rods and disks. For binary mixtures with small particle shape differences, the mixture stresses are bounded by the stresses of the two corresponding monodisperse systems. However, for binary mixtures with large particle shape differences, the stresses of the mixtures can be larger than the stresses of the monodisperse systems at large solid volume fractions because larger differences in particle shape cause geometrical interference in packing, leading to stronger particle–particle interactions in the flow. The stresses in dense binary mixtures are found to be exponential functions of the order parameter, which is a measure of particle alignment. Based on the simulation results, an empirical expression for the bulk friction coefficient (ratio of the shear stress to normal stress) for dense binary flows is proposed by accounting for the effects of particle alignment and solid volume fraction.

Discrete element method to model cracking for two layer systems

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 101-108
Author(s):  
Daniel Varney ◽  
Douglas Bousfield
Keyword(s):  
Discrete Element Method ◽  
Flexural Modulus ◽  
Single Layer ◽  
Discrete Element ◽  
Flexural Stress ◽  
Layer System ◽  
Three Point Bending ◽  
Moving Force ◽  
Coating Layers ◽  
Element Method

Cracking at the fold is a serious issue for many grades of coated paper and coated board. Some recent work has suggested methods to minimize this problem by using two or more coating layers of different properties. A discrete element method (DEM) has been used to model deformation events for single layer coating systems such as in-plain and out-of-plain tension, three-point bending, and a novel moving force picking simulation, but nothing has been reported related to multiple coating layers. In this paper, a DEM model has been expanded to predict the three-point bending response of a two-layer system. The main factors evaluated include the use of different binder systems in each layer and the ratio of the bottom and top layer weights. As in the past, the properties of the binder and the binder concentration are input parameters. The model can predict crack formation that is a function of these two sets of factors. In addition, the model can predict the flexural modulus, the maximum flexural stress, and the strain-at-failure. The predictions are qualitatively compared with experimental results reported in the literature.

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