Maximum Particle Generation Rate in EDEM

Dear Sir/Madam,

In the simulation, I set the particle size as 70um (as the minimum particle volume is 10^-12 m^3) and the particle generation rate as 1 million per second. However, I found that there are not so many particles in the geometry when completing a 1-second simulation. Therefore, I am wondering whether there is a maximum limit for the particle generation rate or particle number in the simulation.

Best Regards,

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v2022.2

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Stefan Pantaleev_21979

Hi Yu,

The EDEM factory algorithm will attempt to place a particle of a given size a number of times in such a way as to not have the new particle overlap with exiting particles. The number of attempts is defined in the factory settings:

If the particle cannot be placed within the factory without any overlaps within the defined number of attempts EDEM will not generate that particle and it will be marked as "failed" in the EDEM solve report.

The algorithm can struggle to place particles if the factory is too small and/or the particle generation rate is too large to allow sufficient empty space in the factory. This will result in reduced generation rate relative to the specified one, a skewing of the particle size distribution towards smaller particles relative to the specified one and increased computational expense.

This video provides further details: https://www.youtube.com/watch?v=T9RJ_3uf0us

To remedy this you can:

1. Increase the size of the factory

2. Reduce the particle generation rate

3. Increase the initial particle velocity

4. Increase the number of attempts for placing a particle (limited and expensive)

Best regards,

Stefan

Yu Wang_21521

Hi Yu,

The EDEM factory algorithm will attempt to place a particle of a given size a number of times in such a way as to not have the new particle overlap with exiting particles. The number of attempts is defined in the factory settings:

If the particle cannot be placed within the factory without any overlaps within the defined number of attempts EDEM will not generate that particle and it will be marked as "failed" in the EDEM solve report.

The algorithm can struggle to place particles if the factory is too small and/or the particle generation rate is too large to allow sufficient empty space in the factory. This will result in reduced generation rate relative to the specified one, a skewing of the particle size distribution towards smaller particles relative to the specified one and increased computational expense.

This video provides further details: https://www.youtube.com/watch?v=T9RJ_3uf0us

To remedy this you can:

1. Increase the size of the factory

2. Reduce the particle generation rate

3. Increase the initial particle velocity

4. Increase the number of attempts for placing a particle (limited and expensive)

Best regards,

Stefan

Dear Stefan,

Thank you for your great help!!! I will try those solutions to tackle the issue. Moreover, I am wondering whether it is possible to add an additional particle factory inlet, so that there will be more factories generating the particles at the same time, and the particles will not have overlaps with each other during the generation process.

Best Regards,

Stefan Pantaleev_21979

Dear Stefan,

Thank you for your great help!!! I will try those solutions to tackle the issue. Moreover, I am wondering whether it is possible to add an additional particle factory inlet, so that there will be more factories generating the particles at the same time, and the particles will not have overlaps with each other during the generation process.

Best Regards,

Yu

Hi Yu,

Having a larger number of factories with lower generation rates can also be a solution but in general n factories with a V/n volume operating at G/n generation rate will behave in a similar way as a single factory of volume V and a generation rate G.

Best regards,

Stefan