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EDEM Simulator
EDEM Simulator is a powerful solver used for fast and efficient simulations.
Set Simulator Parameters
You can set simulation parameters such as the Time Step, simulation time, grid options, and Simulator Engine for the CPU mode, along with the GPU parameters.
Time Steps
A Time Step is the amount of time between iterations (calculations) in EDEM Simulator.
Select a Time Step
Generally, a Time Step is selected as a percentage of the Rayleigh Time Step value. The normal range is 10%-40% of the Rayleigh Time Step.

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.
- Set Simulator Parameters
  You can set simulation parameters such as the Time Step, simulation time, grid options, and Simulator Engine for the CPU mode, along with the GPU parameters.
  - Time Steps
    A Time Step is the amount of time between iterations (calculations) in EDEM Simulator.
    - Select a Time Step
      Generally, a Time Step is selected as a percentage of the Rayleigh Time Step value. The normal range is 10%-40% of the Rayleigh Time Step.
  - Set Data Save
    You can configure settings that determine the simulation data saved, the type of data to be saved, save interval, and data compression.
  - Export Simulation Results
    While running simulations, you can export simulation results to assess the behavior of the simulation during processing without the need for stopping and post-processing in EDEM Analyst.
  - Simulator Grid (CPU Engine only)
    The main computational challenge in DEM simulations is the detection of contacts. EDEM Simulator can examine each cell and analyze only those that contain two or more elements (and hence a possible contact) by dividing the domain into grid cells, saving processing time.
  - Track Collision Data
    During a simulation, EDEM can record data about both contacts and collisions.
  - Preserve Contact Between Triangles
    You can preserve the contact history for a particle passing from one element to another.
- Start and Stop a Simulation
  The current simulation time along with all the previous time steps are displayed in the Viewer Controls pane.
- Dynamic Domain
  When you define a Geometry object as a Dynamic Domain, all material inside the object will be active, and EDEM excludes any stationary material outside the object from any calculations, therefore, improving simulation speed. Dynamic Domain is based on the method outlined in Mio et al., 2009.
- Select the EDEM Simulator Engine
  You can run a simulation in CPU or GPU engine mode. However, the GPU mode requires supported GPU hardware.
- Run EDEM in Batch Mode
  EDEM's Command Line Interface allows you to run EDEM in batch mode without using the GUI.
- Reduce Simulation Time
  The time taken by the Simulator to perform a single iteration, t_iteration, is affected quite significantly by the simulation parameters.
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.
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.

Select a Time Step

Generally, a Time Step is selected as a percentage of the Rayleigh Time Step value. The normal range is 10%-40% of the Rayleigh Time Step.

To select a Time Step:

In the Simulator Settings dialog box, specify the following details:


For	Specify
Time Step
Time Integration	Select the appropriate time integration scheme. Options are: Euler, Position Verlet, and Velocity Verlet. Euler is a first-order time integration method and is used as the default time integration method for EDEM. Position Verlet and Velocity Verlet are integration methods of second order. Velocities and positions are calculated for time steps which are t/2 apart. The Verlet methods come at a slight additional computational cost (up to 10%). However, the methods come with increased computational accuracy. Note: These methods are compatible only with Multi-Spheres.
Auto Time Step	Select this checkbox to automatically adjust the Rayleigh Time Step to the smallest radius that is currently in the simulation rather than the smallest radius to be created. It uses 20% for this particle size. For example, a simulation that has 10mm particles from t=0s and 3mm particles from t=3s will use 20% of the Rayleigh Time Step obtained with 10mm until time 3s, when it would be updated to the Time Step value obtained with 3mm.

Set the Simulation Time

The simulation time is the amount of real time your simulation represents.

To set the simulation time:

In the Simulator Settings dialog box, specify the following details:


For	Specify
Simulation Time
Total Time	Specify the total actual length of the simulation in seconds or minutes.
Required Iterations	Indicates the number of iterations required to complete a simulation of a defined time using the defined Time Step. For example, 5e+05 iterations are required to produce one second of simulation with a Time Step of 2e-06.