Particles reentered cfd domain during events on 1 way fluent coupling in rocky

[baocong.jing]

Hi gangs,

There were issues reported at simulation log "particles reentered the cfd domain during events" after CFD coupling starts on 1 way fluent coupling in rocky at each time interval.

This modelling is about large amount of small particles suction from container via duct (fluent domain) by vacuum that was computed in fluent, in addition to velocity and pressure in fluid phase exported to rocky on 1 way fluent coupling. The duct geometry (wall) was imported from the fluent case.file in alignment with the imported rocky export from fluent.

The CFD coupling started after all particles were successfully loaded and settled in the container with NO particles passing or falling through geometries (walls).

I appreciate any thoughts of that reported issues on particles reentered the cfd domain with what and why.

 

[Jackson Gomes]

Hi,

This message is logged by Rocky whenever a particle crosses back into the CFD domain boundary after having been outside it. In asuction-from-container setup, this is expected behavior particles near the duct inlet face oscillate around the domain boundary as thecoupling applies fluid forces.

It is not related to wall penetration. A few things worth checking:

 - Geometry alignment between the Fluent mesh inlet face and the Rocky wall
 - DEM timestep size relative to particle size and fluid velocity
 - Whether a transient (rather than steady-state) Fluent solution is being used

In 1-way coupling this is non-fatal, but if it appears at every interval, it typically means a group of particles is persistently sitting at the domain boundary which is physically expected in this type of model.

 

Hope this helps! 

If you'd like to explore more learning materials about Rocky software, you can find them here: https://innovationspace.ansys.com/ais-rocky/

Warm Regards,

Jackson