Relative Velocity Used in EDEM

Renan Calmon_22507

Hello everyone,

I was analysing some particles during a collision and it seemed like that the relative velocity calculated by EDEM didnt take into account the angular velocity of the particles. Is this correct? How does EDEM calculate the relative velocity of the collision?

Regards,

Renan

Stephen Cole

Hi Renan,

During contact/collision different contact models can take different inputs, however typically (for example Hertz-Mindlin model) the Relative Velocity at the Contact Point is used to calculate the normal and tangential relative velocity of the elements.

The relative velocity at the contact point takes into account the angular velocity of the particle element.

 

You can see the source code for the Hertz-Mindlin model here - https://community.altair.com/community?id=kb_article_view&sysparm_article=KB0113635

 

If you query Particle velocity in the EDEM Analyst it will return the velocity at the particle Centre of Mass (not the contact point) in which case it does not include the angular velocity component.

 

The EDEM Help > Appendix gives a list and description of available queries for graphing/export.

 

Regards

Stephen