Particles ending up inside geometry

Unknown

Hi all,

 

i have a mixing application where i have a mixing tool with 20 m/s rotational velocity. I see that particles end up inside the mesh of the mixing tool. How can this be prevented? The Rayleigh time step was tested with 20%, 10% and 1% so far.

Is there a guideline for fast rotating geometries?

 

Thanks!

Stefan Pantaleev_21979

Hi Clemens,

It could be a question of contact stiffness rather than timestep. If your numerical particles are softer than the physical ones they may have insuffcient stiffness to resist the penetration. A good approach in this case is to stiffen the geometry (increase geometry shear modulus) rather than the particles so that the solve time is not affected.

Best regards,

Stefan

Stefan Pantaleev_21979

Hi Clemens,

It could be a question of contact stiffness rather than timestep. If your numerical particles are softer than the physical ones they may have insuffcient stiffness to resist the penetration. A good approach in this case is to stiffen the geometry (increase geometry shear modulus) rather than the particles so that the solve time is not affected.

Best regards,

Stefan

Unknown

Stefan,

 

thanks a lot for your (very) quick reply. It is indeed solved i think... I increased the Young's Modulus of the material to 1e15 from 1e6 and the particles seem to be OK and not inside the geometry!

 

Cheers!

Stefan Pantaleev_21979

Clemens Lischka_20358 said:

Stefan,

 

thanks a lot for your (very) quick reply. It is indeed solved i think... I increased the Young's Modulus of the material to 1e15 from 1e6 and the particles seem to be OK and not inside the geometry!

 

Cheers!

Good to hear! Maybe worth considering increasing the geometry stiffness instead so that the timestep is not affected. This will speed-up the simulation.

Best regards,

Stefan