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how to install cuda driver on linux (red hat)
hello i am trying to activate cuda solver on altair edem 2025 on red hat linux
But i keep getting this error.
Please tell me how to fix this
The device has this version of cuda
please tell me which driver should i install and how?
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EDEM API: Particle Body Force - Particle Growth Cycle
Overview
This API allows you to simulate any kind of particle expansion/growth/swelling and shrinkage in EDEM. There is also an example attached that shows the usage of the API.
Usage/Installation Instructions
* Extract the zip file attached. Copy the 'ParticleGrowthCycle.dll' and 'ParticleGrowthCycleInput.txt' from the 'example' folder to the directory of your EDEM simulation.
* Add the plugin model in 'Particle Body Force' of the Physics section.
* You must enter three different values - expansion/shrinkage rate, final scale and start time of the expansion/shrinkage, in the preference file (ParticleGrowthCycleInput.txt).
Use negative values for shrinkage. Higher the rate, faster the process.
* You can have multiple lines of the values to indicate different cycles of swelling and shrinkage in your simulation. Note that you can have a maximum of 40 rows only.
All the particles in your simulation will grow/shrink at the rate you specify in the preference file.
Post-Requisite
If you are interested in just the expansion/shrinkage once, and not necessarily the cycle of expansion/shrinkage, you can refer to this API: https://community.altair.com/community/en/edem-api-particle-body-force-particle-growth?id=kb_article&sysparm_article=KB0122138
You will also be able to add different rates for different particles using the linked API.
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Issue running edem on hpc?
When i try to run a case why do i keep getting this issue
application failed to start because no Qt Platfrorm plugin could not be initialized.
It worked once or twice why is it not reliable to work every time?
I have even reinstalled the application
i cant even run it in batch mode forget GUI why does such a thing happen on Linux? and How to fix this?
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Importing velocity field from external software
Hi everyone,
I am developing an erosion simulation with the Oka wear model; in this case, my simulation includes external results from COMSOL (just the velocity and vorticity fields). I carried out several simulations, and through refinement, I realized that the particles are following just one plane direction. My hypothesis in this case is that the imported field is not refined enough; the original CFD model considers a 2D geometry, and the resulting field is converted to a 3D field with the exporting tools from the software (Comsol). In this case I want to ask if this hypothesis can be correct or if the resulting erosion makes sense according to the conditions presented.
The included images correspond to the 3D velocity field included in the simulation, the main plane corresponding to the 2D field, and the resulting worn pattern.
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Importing Motions from MotionView into EDEM
Overview
Introduction
Currently the only way to bring a motion from MotionView into EDEM is the MotionView-EDEM coupling. The main issue with this approach is that when using the coupling in this way EDEM and MotionView need to constantly exchange data about particles and geometries, which can greatly slow down the simulation.
Instead of using the coupling for bringing these complex motions EDEM it could be more efficient to read the motions created in MotionView and then use python with EDEMpy to create multiple EDEM kinematics that will then replicate the motion in EDEM.
Despite being faster to run there are a couple of downsides to this method.
* Since the interactions between particles and the MotionView bodies won't actually be simulated, any effect from particle interactions or particle weight won't be carried over to the motions.
* Since EDEM can only do simple kinematics, a large number of kinematics is required to recreate complicated motion.
How the Script Works
The script works by getting a list of geometry positions and rotations for each timestep in a MotionView Simulation and then generating a kinematic in EDEM for each timestep where the body changes position or rotation.
For example, if a box is in position (0,0,0) at 0s and at position (5,0,0) at 1s, then the script will create a kinematic for that geometry with the following parameters:
* Start Time: 0 s
* End Time: 1 s
* Velocity: 5 m/s
* Direction: (1, 0, 0)
A very similar method is followed for rotating the geometry, allowing the geometry to follow any path described in a MotionView simulation.
Pre-Requisite
Have EDEM 2024 or later installed.
Have EDEMpy 1.5 or later installed.
Usage/Installation Instructions
Script Inputs
This script requires 3 files to run:
* An EDEM deck containing the geometries that the kinematics are to be added to.
* A .plt or .csv file containing the output of the position and rotation of the geometries.
* A preference file.
The next section will go into detail on what is specifically required for each of these files and how to create them.
EDEM Deck Setup
The only setup requirement for the EDEM deck is that it has all the geometries that are going to be used in the simulation, and that these geometries have the same name as used in the motion input file.
One way to do this would be with the EDEM Import Geometry function, these geometries can then be renamed to match the body names in the .plt or .csv file.
If the motion view simulation is setup and contains many parts that would be time consuming to import into EDEM, then the same result can be achieved by using the coupling interface.
Turn on the coupling server on the EDEM side, and then add an EDEM subsystem in the analysis tab of MotionView. In this subsystem select all the Bodies that are to be used in the EDEM simulation.
This will copy the geometries over to EDEM, the coupling can then be disabled and the geometries will still remain in EDEM.
Save the deck once the geometries are in place and appropriately named.
Motion File Setup
There are two file formats accepted for the file containing the positions of the geometries at each timestep .plt and csv.
.plt File Creation
The .plt file can be generated by MotionView using the Output button in the Analyze Tab.
To be read by the python script the output needs the following settings:
* Type: Displacement. This outputs the positions and rotations.
* Subtype: Entity Set. This tells MotionView to output the positions for each entity of a specific type
* Entity Set Type: Bodies. The entity set of interest is bodies
* Reference Marker: Global Frame. The displacement is all relative to the global reference frame.
Once the output has been specified then the MotionView Analysis can be run again and a .plt file will be created in the same folder as the rest of the MotionView outputs. The file should look similar to this, with the bodies being listed first and then data for their position and rotation being listed for each timestep of the motion view simulation.
The position and rotation are described by 6 numbers, the first 3 of which are x, y, and z position. The second 3 numbers are Euler angles of the geometry in the zxy format.
.csv File Creation
The .csv file can be generated without any need for MotionView but it follows a similar format for describing the positions and angles, and has 8 columns that need to be filled:
* The first column is the timestep.
* The second column is the name of the body.
* The 3rd, 4th, and 5th columns are the position of the body at that time.
* The 6th, 7th and 8th columns are the rotation of the body at that time, using the Euler angle zxy format.
Preference File Options
The preference file template is attached, and there are 5 options that need to be edited depending on the simulation setup.
The first two settings are the file names of the simulation deck and the motion file. The second two settings relate to the unit conversion between the motion file and EDEM. Since EDEM uses m and radians as its base units then the script needs to know what units the motion files uses so they can be properly converted.
The final setting is slightly more complicated and is to do with how the script reads the .plt file. The script reads the file line by line and needs to look for a specific bit of text to indicate when the useful data of the file starts. In this case that is the name of the first body listed in the output file, this first listed body should normally be "Ground Body", but this sometimes differs so it is worth checking the .plt file before running the script.
Running the Script
Go to the Analyst tab and click on File, Run EDEMpy script and select the script. Note that the deck, script, motion file and preference file should be in the same folder. Run the script. A command prompt will open showing the script running.
To see the modified EDEM deck it will have to be reopened.
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License issues with EDEM
Hi,
One of our clients asked altair for a trial license for 1 month to use EDEM to see if it suits their needs.
But when they try to launch the software, those error messages appear.
Do you know what is causing this issue ? How can we solve it ?
Thanks in advance,
Kinds regards,
Loïc Verhaeghe
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Nut Mixing and Packaging System Simulation in EDEM - Material Dosing
A significant proportion of food produced globally is never consumed, with around 14% lost between production and retail [1]. While food loss can occur at various stages of the supply chain, improving bulk material handling in food processing—through virtual testing and system optimization—can help reduce losses and improve production efficiency.
Designing an effective particle dosing and packaging system presents several challenges, including:
* Controlling Particle Movement
* Preventing Segregation
* Precise Release Mechanisms
* Optimizing Efficiency & Reducing Waste
This blog post demonstrates how Altair® EDEM™ can be used to simulate a nut packaging system (see Figure 1), offering insights into particle behavior and providing a virtual environment to evaluate and optimize the feeding process prior to packaging.
Figure 1 – Simulation of the nut packaging system
The simulation deck corresponding to the nut mixer example is provided below:
Nut Mixer and Dosing System.zip
How EDEM Enables Smarter Feeding System Design
Altair® EDEM™ enables engineers to build detailed DEM simulations that replicate bulk material behavior in processes such as handling, feeding, and mixing. It provides a virtual environment to assess system design and optimize material flow.
Simulations help improve efficiency, reduce segregation, and minimize material loss—while avoiding the cost and time of physical prototyping.
For new users, a summary of key learning resources is available in the blog post linked below:
4 Steps to Accelerate your Learning
Step 1: Setting the Material Model
The first step is to define the material properties for both the nut particles—almonds, pistachios, walnuts, hazelnuts, and cashews—and the system components. These properties govern how all materials interact and move within the simulation.
While material calibration is typically recommended in EDEM to improve accuracy and reflect real-world behavior, this example uses non-calibrated models with realistic values for each nut type, which are sufficient for demonstrating system behavior and particle interactions in this context.
Users looking to explore calibration in more detail can refer to the resources below:
Calibration Blog Post - Discrete Element Method Calibration with EDEM
Calibration eLearning Videos – EDEM Calibration eLearning
Step 2: Defining Particle Shape Using Polyhedral Particles
Accurately representing particle shape is crucial, as it directly impacts how materials flow, stack, and mix. In this simulation, all nut types—almonds, pistachios, walnuts, hazelnuts, and cashews—were modelled as concave polyhedral particles, created as 3D CAD models and imported into EDEM.
Using polyhedral particles allows for a more realistic capture of each nut's unique shape and surface detail (see Figure 2), which supports more accurate modeling of mixing and segregation. However, this approach comes with increased computational cost compared to simpler shapes like multi-sphere particles.
Figure 2 – A section of walnuts on the conveyor; made using Altair® Inspire™ Studio
While the materials were not calibrated, the coefficient of static friction was adjusted to reduce excessive sliding, and the coefficient of restitution was tuned to minimize unrealistic bouncing during interactions.
Step 3: Importing CAD Geometry
EDEM supports various CAD file formats, including STL, STEP, and IGES, allowing users to import custom equipment models (see Figure 3).
Geometries can be imported via Creator > Geometries > Import Geometry and are automatically meshed unless the format already includes a predefined mesh. While mesh size generally has minimal impact on DEM results, manual mesh adjustments may be useful for wear analysis or detailed contact interactions as wear is plotted per triangular mesh element.
Figure 3 – CAD model of nut mixer in EDEM
Step 4: Introducing Material
To ensure a continuous supply of nuts, all particles are introduced using dynamic factories positioned over the central plate. Each factory geometry is shaped to match its designated 1/5th section of the decagonal plate and is defined in EDEM as a virtual geometry (see Figure 4). This allows each factory to more precisely conform to its section, enabling smoother and more even particle distribution than default EDEM shapes such as polygons or cylinders, which may not accurately reflect the section's geometry. This setup keeps the central plate consistently full, allowing nuts to accumulate before reaching the conveyors.
A small initial velocity is also applied in the vertical (Z) direction to reduce particle overlap and improve factory efficiency.
Figure 4 – Top view of system; showcasing factory geometries and generated nuts
Step 5: Assigning Kinematics
Different kinematic motions are assigned to control nut movement throughout the system (see Figure 5):
Sinusoidal Motion on the Central Plate
* A constant sinusoidal vibration is applied in the vertical (Z) direction, allowing nuts to slowly move evenly in the horizontal direction and onto the conveyor plates.
Linear Conveyor Motion on Conveyor Plates
* At the start and to get the system to reach steady-state sooner, a linear conveyor motion is used to move nuts closer to the ends of the conveyors, positioning them near the catchers.
Sinusoidal Vibrations (Bursts) on Conveyor Plates
* Periodic sinusoidal bursts applied across entire conveyors to push nuts into catchers in controlled amounts, preventing excessive material flow.
Rotating Discharge Plate in Catchers
* Each catcher is equipped with a rotating discharge plate at its base, which briefly opens when a defined torque threshold is exceeded. This allows the nuts to drop into the hopper before the plate quickly closes again, enabling controlled, mass-responsive release and helping maintain the desired proportions in the final mix.
Figure 5 – Overview of kinematic motions applied throughout the system
Step 6: Post-Processing
EDEM allows engineers to analyse and extract various pieces of key information, these include but are not limited to:
* Mass flow rate of nuts per ejection.
* Total mass of nuts in the discharge hopper.
* Mixing uniformity/ratio in the discharge hopper.
* Prediction of wear hotspots and amount of wear on the system.
* Particle trajectories/pathlines to identify and eliminate potential dead zones.
* Velocity of nuts at any point in the system (see Figure 6).
Users interested in a detailed overview of EDEM’s post-processing features can refer to the following blog post:
EDEM Post-Processing: How to analyze your EDEM simulation results
Figure 6 – Velocity coloring of nut particles
Conclusion
This blog post showcased the use of EDEM to simulate and analyze a bulk material handling process for nuts, focusing on the mixing and dosing stages—from material setup through to kinematic control and post-processing. By leveraging EDEM’s capabilities, users can gain valuable insights into particle behavior and optimize their bulk material handling systems for improved efficiency and performance.
Further Readings
Below are links grouped into two focus areas:
Enhancing Simulation Setup and Performance:
* Factors affecting simulation runtime in EDEM – EDEM Simulation Run Time
* Estimating runtime of an EDEM simulation – Estimate Simulation Runtime
* Documentation on reduction of simulation time – Reduce Simulation Time
Other Related Readings that may be of Interest:
* Optimizing pharmaceutical manufacturing using EDEM – Pharmaceutical Manufacturing
* Analysis and optimization of bulk solids mixing systems with EDEM – Optimization of Bulk Solids Mixing
* Effect of material properties on blend uniformity – Blend Uniformity
References:
[1] Food Health Organisation. The State of Food and Agriculture. (2019). https://openknowledge.fao.org/server/api/core/bitstreams/11f9288f-dc78-4171-8d02-92235b8d7dc7/content
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unable to activate license
Hello
I installed altair edem 2025 on one of the new computer at the university and i keep getting this error when ever i try to access edem
please tell me how to fix this
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Optimization of solving time: EDEM wear simulation
I am modeling an erosion machine; in this case, the general geometry is just representative to indicate the limits of the simulation. The most important parts are the factory corresponding to the little circle at the end of the injector and the sampling plate. I am including the velocity and vorticity field and considering sand particles. The main objective is to accurately predict wear in the sampling plate, but the simulation is taking a lot of time since the mesh is around 0.15 mm (similar to sand size). Also, I am simulating in a workstation with an AMD Ryzen Threadripper PRO 3945WX 12-Cores, 64 GB RAM, and a P2000 graphics card. I am using a CUDA solver in this case, but I want to ask about some recommendations to improve simulation speed. I am thinking of reducing the limits and developing an axisymmetric simulation, and maybe use a coarser mesh but I dont know if it can change a lot in the wear results.
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How tangential slip distance is calculated in the archard wear model
How is the tangential slip distance calculated in the archard wear model? Was it extracted from the contact model? Hope to get a detailed answer, thank you