Comparative analysis of porosity coarse-graining techniques for discrete element simulations of dense particulate systems
File(s)
Accepted version
Author(s)
Kalderon, Moris
Smith, edward
O'Sullivan, Catherine
Type
Journal Article
Abstract
The discrete element method (DEM) is a well-established approach to study granular materials in numerous fields of application; each granular particle is modelled individually to predict the overall behaviour. This behaviour can be then extracted by averaging, or coarse graining, the sample using a suitable method. The choice of appropriate coarse-graining method entails a compromise between accuracy and computational cost, especially in the large-scale simulations typically required by industry. A number of coarse-graining methods have been proposed in the literature, and these are reviewed and categorized in this work. Within this contribution, two novel porosity coarse-graining strategies are proposed including a voxel method where a secondary dense grid of “pixel cells” is implemented adopting a binary logic for the coarse graining and a hybrid method where both analytical formulas and pixels are utilized. The proposed methods are compared with four coarse-graining schemes that have been documented in the literature, including the particle centroid method, an analytical method, a method which solves the diffusion equation and an approach which employs averaging using kernels. The novel methods are validated for problems in both two and three dimensions through comparison with the “accurate” analytical method. It is shown that, once validated, both the proposed schemes can approximate the exact solutions quite accurately; however, there is a high computational cost associated with the voxel method. The accuracy of both methods can be adjusted allowing the user to decide between accuracy and computational time. A detailed comparison is then presented for all six schemes considering “accuracy”, “smoothness” and “computational cost”. Optimal parameters are obtained for all six methods, and recommendations for coarse-graining DEM samples are discussed.
Date Issued
2022-02-01
Date Acceptance
2021-03-10
Citation
Computational Particle Mechanics, 2022, 9, pp.199-219
ISSN
2196-4378
Publisher
Springer
Start Page
199
End Page
219
Journal / Book Title
Computational Particle Mechanics
Volume
9
Copyright Statement
© 2021, OWZ. The final publication is available at Springer via https://link.springer.com/article/10.1007/s40571-021-00402-4
Sponsor
Engineering & Physical Science Research Council (E
Grant Number
EP/P010393/1
Subjects
Science & Technology
Physical Sciences
Technology
Mathematics, Interdisciplinary Applications
Mechanics
Mathematics
Granular materials
Discrete element method
Homogenization
Numerical simulations
Coarse graining
FLUIDIZED-BED
CFD-DEM
NONSPHERICAL PARTICLES
NUMERICAL-SIMULATION
SURFACE FLOW
COUPLED CFD
VALIDATION
ALGORITHMS
FIELDS
STRAIN
Publication Status
Published
Date Publish Online
2021-06-23