Reno Genest
Ansys Employee

Hello Weidong,

There is an example of a sphere dropped in water here:

It is not DEM, but if you have only one sphere, you could mesh the sphere with regular elements and have the sphere rigid:

You will find papers here:

https://apps.dtic.mil/sti/pdfs/AD1011313.pdf

https://www.dynalook.com/conferences/15th-international-ls-dyna-conference/fsi-ale/comparative-analysis-of-occupant-responses-between-ls-dyna-r-arbitrary-lagrange-in-euler-and-ale-and-structured2013ale-s-ale-methods/view

https://www.dynalook.com/conferences/14th-international-ls-dyna-conference/blast/comparison-of-strategies-for-landmine-modeling-in-ls-dyna-with-sandy-soil-material-model-development/view

You can search for more papers on dynalook.com website.

Also, DEM particles can be coupled with the iCFD (incompressible CFD) solver in LS-DYNA:

https://www.dynaexamples.com/icfd/basics-examples/demcoupling

 

Reno.