# Collapsible Tube (OpenFOAM+CalculiX)

**URL:** <https://precice.discourse.group/t/collapsible-tube-openfoam-calculix/1334>\
**Category:** Official adapters and tutorials\
**Tags:** openfoam, calculix, fsi\
**Created:** [March 20, 2023, 3:50pm UTC](https://precice.discourse.group/t/collapsible-tube-openfoam-calculix/1334 "2023-03-20T15:50:59Z")\
**Posts on this page:** 1\
**Page:** 4

<div class="post-metadata">

**Author:** ![Makis](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/makis/32/25_2.png) [@Makis](https://precice.discourse.group/u/Makis)\
**Post date:** [October 14, 2023, 9:16pm UTC](https://precice.discourse.group/t/collapsible-tube-openfoam-calculix/1334/62 "2023-10-14T21:16:22Z")

</div>

I don’t think there is any particular reason for choosing the one over the other. Some aspects to consider:

- Some solvers only provide relative displacements, some only provide absolute displacements. We try to support both, wherever possible.
- Our tutorials have historically evolved mostly based on what each student project needed, and not as a predefined “curriculum”. Reasons are often historical.

I guess that there may be numerical reasons that make the relative displacements better in some scenarios. But I have no idea what the literature has to say in this regard.

[Previous page](https://precice.discourse.group/t/collapsible-tube-openfoam-calculix/1334.md?page=3)