Introduction

Aspherix® is a product family that combines a high performance Discrete Element Simulation engine (Aspherix® Solver) with a graphical user interface (Aspherix® GUI) and a tool that is dedicated to material calibration (Aspherix® Calibration). One-way coupled CFD-DEM calculations can be run directly with Aspherix® Solver, for four-way coupled CFD-DEM simulations DCS Computing provides CFDEM®coupling.

Aspherix® Solver is partially based on the popular open-source DEM software LIGGGHTS® and LAMMPS® and was extended by numerous cutting-edge capabilities. It is designed to handle numerous particle shapes (spheres, multispheres, tablets, boxes, ellipsoids, fibers, bonded particles, convex triangulated objects, concave triangulated objects, …):

_images/particle_shapes.png

It offers the user a large variety of different models and tools that allow for the efficient simulation of different application cases. Some highlights are the following:

  • Load balancing: a smart algorithm ensures that the available resources are used most efficiently. This improves the usability of Aspherix® Solver for HPC even further and ensures the applicability of the software to industrial scale problems.

  • Advanced contact models: real materials often follow complex contact laws. Aspherix® Solver provides a large collection of models that permit the modeling of powders, asphalt, flexible fibers (including breakage), liquid bridges, cohesive soils and many others.

  • Multi-phase modelling: in many cases granular materials interact with liquids and gases. There is a multitude of different flavours of multiphase problems, and Aspherix® Solver provides different solution approaches, be it spray modelling, one-way coupling (with the possiblity to use a series of fluid velocity fields for transient applications or a moving reference frame zone) or an interface to a CFD solver for fully coupled CFD-DEM simulations.

This image gives a small overview of some application examples:

_images/application_examples.png

Aspherix® Solver uses a human-understandable script input language, termed “natural language”. However, in many cases a graphical user interface is useful for case setup and maintainance. For this purpose, Aspherix® GUI was created. Apart from guiding the user through the setup process it also provides many little helpers such as design tools for multisphere and superquadric particles (see image below) or a mesh cleanup tool.

_images/sq-builder.png

A real-time display of the most imporatant global parameters of a calculation such as number of particles, kinetic energy, etc. gives the user an overview of the current state of the simulation. The direct link to the postprocessing tool Paraview and an auto-generated case-loading script make postprocessing much easier.

Properties that characterize granular materials can be divided into two groups, namely into those that can be measured directly (density, particle size distribution, Young’s modulus etc.) and those that can only be determined indirectly (coefficient of friction, coefficient of rolling friction, cohesivity, etc.). For determining the latter, materials need to be characerized. With Aspherix® Calibration, DCS Computing provides a capable tool that can take over this part!

Products