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Coupling Interface Programming Guide
The Coupling Interface Programming Guide provides an overview of how to use the EDEM Coupling Interface to couple with a generic CFD code and/or Multi Body dynamics codes.
Coupled EDEM-CFD Simulation
EDEM integrates fluid drag forces and torques into the particle simulation on an individual particle level.
Use the Sampling Point Method
The Sampling Point method is not used in the latest version of the EDEM-Fluent coupling, but the corresponding functions and code are still available for implementation in your own code. The distribution of particle volumes is currently handled natively within Fluent.

Welcome
What's New
New features and enhancements available in EDEM.
Release Notes
This document contains information about the EDEM release, such as key features and enhancements, bug fixes, and known issues.
About EDEM
EDEM is a high-performance simulation software for bulk and granular materials.
Get Started with EDEM
The EDEM user interface comprises three icons for each simulation component - Creator, Simulator, and Analyst.
EDEM Creator
EDEM Creator is the pre-processor for creating an EDEM simulation model, including setting up equipment and defining the generation of bulk materials.
EDEM Simulator
EDEM Simulator is a powerful solver used for fast and efficient simulations.
EDEM Analyst
EDEM Analyst is the post-processor used to analyze and visualize the results of your simulation.
EDEM Contact Models
A Contact Model describes how elements behave when they come into contact with each other.
EDEM Cal Utility
EDEM Cal is a utility which works with EDEM and is designed to assist in performing calibration.
GPU CUDA Guide
The EDEM CUDA GPU module uses the latest General Purpose Computing on Graphical Processing Units (GPU) technology.
Programming Guide
The EDEM Programming Guide describes the EDEM API.
Coupling Interface Programming Guide
The Coupling Interface Programming Guide provides an overview of how to use the EDEM Coupling Interface to couple with a generic CFD code and/or Multi Body dynamics codes.
- Enable and Run the Coupling Server
  The EDEM Coupling Server options are accessible from the top-right corner of the EDEM window.
- Start and Stop the Coupling Server
  By default, EDEM will launch with the Coupling Server stopped and requires you to start the server before a coupled simulation can proceed.
- Run a Compiled Application
  When running your compiled application, you must ensure that the EDEM libraries can be correctly picked up, You must add the location of the EDEM libraries to theLD_LIBRARY_PATH environment variable.
- Coupled EDEM-CFD Simulation
  EDEM integrates fluid drag forces and torques into the particle simulation on an individual particle level.
  - Retrieve Particle Data from EDEM
    You can retrieve particle data from EDEM using the getParticleData method. This method will return the data for all the particles currently in the simulation. The operation is usually performed at the end of the EDEM simulation step, after the position of the particles has been updated.
  - Use the Sampling Point Method
    The Sampling Point method is not used in the latest version of the EDEM-Fluent coupling, but the corresponding functions and code are still available for implementation in your own code. The distribution of particle volumes is currently handled natively within Fluent.
  - Set External Force and Torque on Particles
    Particles can have external forces and torques calculated by the external CFD solver applied to them before EDEM executes a simulation-step. This is achieved using the setForceAndTorque method provided by the interface class, IEDEMCoupling.
  - Register a New Custom Particle Property
    You can create custom properties to store new variables that represent particle properties that EDEM does not support natively. Creation of new custom properties allows manipulation both with the CFD Coupling Interface and the custom EDEM API models.
  - Use Custom Particle Properties
    Custom particle properties are stored in arrays that match the particle data array.
- The Multi Body Dynamics Coupling Interface
  The Multi Body Dynamics (MBD) Coupling Interface is a subset of features in the EDEM Coupling Interface specifically designed for coupling EDEM to Multi Body Dynamics packages.
- Design of Experiment-style Studies
  Design-Of-Experiment (DOE) style programs or parametric CAD packages allows equipment designs to evolve through co-simulation. This capability in the EDEM Coupling Interface also allows you to automatically create many simulations containing variations on Geometry or Geometry dynamics for running in batch mode.
- Compile Coupling Interface Code to an Executable
  You can compile simple user-written code into a stand-alone executable to work with the coupling interface.
EDEMpy
EDEMpy is a Python library for accessing EDEM data from .h5 files (the underlying EDEM file format). EDEMpy does not require prior knowledge of advanced programming.
EDEM Solver Capabilities
EDEM contains four solver engines.
Appendix
This section provides additional information about how to estimate simulation time, supported EDEM File types, attribute definitions, and so on.
EDEM Terminology
Definitions of terms used in EDEM.
References and Bibliography
This section cites the contributions made by various authors and sources that have been used as reference material for EDEM, and the specifics of how they have been applied can be found in the individual contact model sections.

Use the Sampling Point Method

The Sampling Point method is not used in the latest version of the EDEM-Fluent coupling, but the corresponding functions and code are still available for implementation in your own code. The distribution of particle volumes is currently handled natively within Fluent.

The drag models used to calculate particle drag forces must also take into account the volume of particles found in each cell of the mesh. To achieve this, you may implement your own solution using custom properties or any other method. However, EDEM provides another easy to use representation of particle volume.

The representation of volume provided by the EDEM Coupling Interface is based on multiple sample points, generated using the Monte Carlo method. EDEM takes regular sample points within the bounding box of a particle and keeps the points that lie within the particles bounding surfaces.

The following diagram represents sample points within a particle.

Each point is checked to determine the CFD mesh cell it lies within. The solid volume fraction within a particular mesh cell is, therefore, the percentage of the number of sample points that lie within that mesh cell defined as:

\in_{s} = 1 - \in = \sum_{p a r t i c l e s} \frac{n_{c}}{N} V_{p}

where n_c is the number of sample points contained within the mesh cell of particle p, N is the total number of sample points of the particle, and V_p is the volume of the particle.

Sample points are generated for each of the particle types defined in the simulation. Using the position, orientation and scaling of the individual particles, the precise co-ordinates for the points representing each particle can be calculated. If there are no additional particle types added later to the simulation, sample points need only be collected once, at the start of the simulation. The method used to request sample points from EDEM is collectSamplePoints.

The sample points for a particle type are returned as an array of 3D values (C3dValue objects) of size n. You must accordingly allocate and delete memory to store the sample points for the simulation.