Best contact model to use in EDEM simulation of planetary ball mill

Kamatchi_S14

Greetings!
I'm new in here and I'm working on planetary ball milling as my project. I'm using ATOMET 4601 as the powder and Tungsten carbide balls to grind the same into finer particles. At present I have the Altair EDEM 2024.1 in my DELL G15 laptop and the full licensed version is available at our University lab. I'm unsure of which model to use for my case. Which models should I use to observe finer particles with minimal wear on the balls and jar.

Renan

Hi Kamatchi,

Please check lesson 7.1 in the EDEM eLearning course to learn which contact model to choose based on the bulk behavior of your material.

EDEM eLearning

Best regards,

Renan

Renan

Hi Kamatchi,

Please check lesson 7.1 in the EDEM eLearning course to learn which contact model to choose based on the bulk behavior of your material.

EDEM eLearning

Best regards,

Renan

Kamatchi_S14

Hi Renan

Thank you for your suggestion to go through the eLearning modules. I have explored them and proceeded with different models to achieve the desired outcome in my planetary ball mill simulation.

I initially used the Hertz-Mindlin (no slip) condition with Bonding V2 as the additional model. However, this setup did not yield the expected results, as I am not looking to break apart clusters or clumps of particles bonded due to cohesive forces. Instead, my goal is to reduce the size of individual particles over time.

Since the Tavares breakage model is commonly used for breaking larger-sized particles into finer ones, I tested it within my simulation. While it does appear to work—since I observed particle breakage—it is extremely computationally expensive. After running the simulation for an hour, only 1% of the computation was completed. Given that my particle size range is 1 to 1.5 mm in diameter, I am concerned that the Tavares model may not be optimal for this scale.

My objective is that the average diameter of particles should decrease progressively over time and by the end of the simulation the number of particles should have increased, indicating successful particle breakage.

Currently, I can see some particles breaking, but the excessive computation time makes it difficult to proceed efficiently. Am I on the right path, and should I simply allow more time for the simulation? Or is there an alternative model that would be computationally faster while still achieving the same results?

I appreciate any insights or recommendations you may have.

Best regards,
Kamatchi S

Renan

Hi Kamatchi,

Using Hertz-Mindlin + Bonding or the Tavares Breakage model are the only two ways to simulate breakage.

Each model has its pros and cons. The HM+Bonding model uses a clump of small particles to represent one large particle, so the total number of particles in your simulation is very all the time and it is also required to calibrate the bond strength.

The Tavares breakage model uses a particle replacement method to replace the big particles with small one when they break. This means that the initial number of particles in your simulation can be smaller but might grow over time. This model is also very computationally intensive and it requires calibration and a small timestep (usually 5% of the Rayleigh timestep). However, you can control what the minimum particle size in your simulation is going to be, which gives you some flexibility and you'd still be able to get the total mass and size distribution of the fines generated using the breakage post processing tool in the analyst.

As I've said, each model has its pros and cons and it is up to you to pick which one you're going to use in your simulations based on your project deadline and the hardware that is available to you.

Best regards,

Renan