# Passing face values during volume coupling

**URL:** <https://precice.discourse.group/t/passing-face-values-during-volume-coupling/2772>\
**Category:** Using preCICE\
**Tags:** openfoam, adapters, data-mapping, fluid-fluid\
**Created:** [February 26, 2026, 1:41pm UTC](https://precice.discourse.group/t/passing-face-values-during-volume-coupling/2772 "2026-02-26T13:41:51Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![dennis](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@dennis](https://precice.discourse.group/u/dennis)\
**Post date:** [February 26, 2026, 1:41pm UTC](https://precice.discourse.group/t/passing-face-values-during-volume-coupling/2772/1 "2026-02-26T13:41:51Z")

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Hello everybody,

assume that I have one mesh (M1) immersed in another (M2) and want to volume couple an OpenFOAM simulation in M1 to another OpenFOAM simulation in M2. How can I pass/interpolate values from simulation M2 to the boundaries of simulation M1 (use this as boundary conditions in M1) and then pass a calculated value from M1 to the cells from M2? I guess this is something like a surface coupling in one direction and volume coupling in the other.

Thanks and all the best,

Dennis

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**Author:** ![dennis](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@dennis](https://precice.discourse.group/u/dennis)\
**Post date:** [February 26, 2026, 1:46pm UTC](https://precice.discourse.group/t/passing-face-values-during-volume-coupling/2772/2 "2026-02-26T13:46:53Z")

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For the micro-manager I was reading out all the face values around a cell and passing them to the micro simulations, but now I want to couple a domain larger than a single cell.

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**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:** [February 26, 2026, 2:28pm UTC](https://precice.discourse.group/t/passing-face-values-during-volume-coupling/2772/3 "2026-02-26T14:28:10Z")

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For the OpenFOAM simulations: everything depends on what `locations` you configure. Configuration:

> **[Configure the OpenFOAM adapter](https://precice.org/adapter-openfoam-config.html)**
>
> Write a system/preciceDict, set compatible boundary conditions, and activate the adapter in your system/controlDict.

I am not sure I follow the model setup, but on the technicalities:

- For M2 to write all of its inner domain values, you need to define an interface with `locations volumeCenters` (assuming that a patch is not enough).
- For M1 to read in patches, configure as usual for surface coupling.
- You then need an appropriate mapping between preCICE meshes.
- For the M1 to M2, configure a source terms, as shown in the documentation.

If in doubt, you can always define multiple `Interfaces` in `preciceDict`.

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/precice/original/1X/67d2a5fa6f80e597e2267ff17fa8c1673cd11caa.svg) [@system](https://precice.discourse.group/u/system)\
**Post date:** [March 1, 2026, 2:28pm UTC](https://precice.discourse.group/t/passing-face-values-during-volume-coupling/2772/4 "2026-03-01T14:28:56Z")

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Closed on March 1, 2026, 2:28pm UTC

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