What's new in EDEM 2021

Let’s have a look at the key features of EDEM 2021!

Polyhedral Particles

Shape plays a critical role in Discrete Element Method (DEM) simulations. For most applications, the well-validated multi-sphere approach is recommended as it offers the right balance of computational efficiency and accuracy. There are; however, some applications for which the use of polyhedral particles can be attractive. These include materials which have a very uniform shape or those that require a large number of spheres to represent – such as particles with a high aspect ratio. With EDEM 2021 users now have access to a new polyhedral particle shape solver as an alternative to the standard multi-sphere solver. The polyhedral particle solver has been designed for high performance cards and runs on Nvidia CUDA® GPU cards. It is compatible with the EDEM API and the coupling interface for coupled simulations with Computational Fluid Dynamics (CFD) and Multi-Body Dynamics solvers.

For more information about the polyhedral particle solver read this article.

Examples using polyhedral particles: chewing gum in drum mixer and pellets in screw auger.

Increased performance

The EDEM multi-sphere GPU solver has been further optimized and this results in a speed improvement of up to 30%. The graph below shows GPU speed-up between EDEM 2021 and previous versions.

GPU speed-up based on EDEM versions.

Volume packing

Many applications require the generation of large beds of materials, for instance for off-road vehicles or agricultural machinery when looking at the interaction with soils or complex terrains that are not flat. The new ‘volume packing’ functionality in EDEM 2021 enables users to auto-generate tightly packed beds quickly and according to specific criteria such as porosity or a given level of compaction. This works for any closed volume geometry and can be applied to arbitrary shapes but also uniform shapes such as cylindrical hoppers. It is a faster method than the traditional way of introducing large amounts of material and, once generated, these beds are saved as material blocks that can be easily introduced at any time during a simulation or re-used in other simulations.

Creating this complex shape would have previously required a long set-up. With the new volume packing capability it is now possible to generate such packed beds within minutes.

Built-in Lift and Drag models for imported Field Data

The ability to import a 3^rd party data field for a one-way CFD coupling has been a key capability of EDEM for many years when looking at particle-fluid applications where the fluid drag is significant but the particle effect on fluid flow is not. The workflow has now been enhanced with the availability of a range of lift and drag models now available directly from the Physics section of the EDEM Creator, within the Particle Body Force dropdown. Users only need to import a velocity field and they will be able to select a model from the list, currently including:

• Saffman lift model
• Magnus lift model
• Schiller and Naumann drag model
• Morsi and Alexander drag model
• Haider and Levenspiel drag model
• Ganser drag model

User workflow enhancements

A range of enhancements have been made to improve and speed up the workflow. That includes the possibility to group several geometry parts and merge geometries, making it easier and faster to manage simulations with lots of parts. On the post-processing side, it is now possible to color particles by Stress, Axial Stress and Von Mises, in order to visualize stress and analyze damage directly in the EDEM Analyst. In terms of usability and ergonomics, support for using a 3D mouse has been added with the option to use SpaceMouse® products by 3dconnexion to modify the 3D viewer in EDEM.

Tire-soil interaction with particles colored by stress

EDEM-AcuSolve 2-way coupling

It is now possible to perform a full two-way coupling between EDEM and AcuSolve to model complex particle-fluid systems such as fluidized beds, pneumatic conveying and solid-liquid mixing where the fluid impacts the particles and the particles also have an effect on the fluid. Particles much larger than the mesh size are permitted. Heat transfer is supported for particle-particle, fluid-particle, and solid-particle interactions.

EDEM-MotionSolve coupling enhancement

Coupling EDEM with Altair MotionSolve enable engineers designing heavy equipment to introduce realistic bulk material in their multi-body dynamics simulations and to get key insight into machine-material interaction. New to this co-simulation is the capability for component model synthesis (CMS)-based flexible bodies to interact with the particles. CMS flexible bodies can represent body deformation in the linear range. Reaction forces due to contact between particles and the flexible body are simulated, which lead to strain and stresses within the flexible body.

Excavator with the bucket as a CMS-based Flexible Body