Hi dear community,

I am currently working on modeling the interaction between water waves and a cylindrical breakwater using the Coupled Eulerian-Lagrangian (CEL) technique in Abaqus.
At the moment, I am preparing a mesh convergence study and have some confusion regarding the appropriate mesh size for both the Eulerian and Lagrangian domains—especially in the contact region.

According to an online course I purchased, it is recommended that:
“A resolution of at least 3–5 elements over the smallest feature dimension in the adjacent Lagrangian domain is recommended.”

In this context, I would like to clarify:

• Does the term “feature” refer to the smallest geometric dimension of the solid Lagrangian body (e.g., wall thickness of the cylinder, diameter of small perforations, or fillet radii) that is in contact with the Eulerian domain?
• Or does it mean that the Eulerian mesh size should be 3–5 times smaller than the Lagrangian element size in the contact area?

I would greatly appreciate any insights, suggestions, or references that could help me carry out this mesh convergence study correctly.

Thank you very much in advance!