With release of preCICE version 3.0.0 up to the latest release of preCICE version 3.2.0 there have been many changes and improvements regarding large meshes.
The following has a positive effect on volume coupling:
- Mesh processing, memory footprint, and communication has been substantially improved.
- Initialization speed of large distributed meshes has been improved thanks to a more efficient repartitioning.
- Radial-basis mappings are now usable with large meshes thanks to the new partition-of-unity mappings.
- The just-in-time mappings provide a convenient and efficient way to map data from/to positions in a region of interest. This is especially useful for particle codes.
A caveat for preCICE 3.2.0 is that implicit schemes now exchange substeps by default to enable time interpolation. If your solver uses subcycling, then the communication cost increases linearly with the amount of substeps. This can be disabled in the <exchange ... substeps="true" /> tags.
Note that volume coupling is being actively used right now.
If you are running into severe performance issues please open a discourse post and let us know.