# Minimal deformation in the event of 100kg tnt explosion

**URL:** <https://precice.discourse.group/t/minimal-deformation-in-the-event-of-100kg-tnt-explosion/2700>\
**Category:** Using preCICE\
**Tags:** openfoam, configuration, calculix\
**Created:** [January 5, 2026, 7:41pm UTC](https://precice.discourse.group/t/minimal-deformation-in-the-event-of-100kg-tnt-explosion/2700 "2026-01-05T19:41:09Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Checa](https://yyz2.discourse-cdn.com/free1/user_avatar/precice.discourse.group/checa/32/2881_2.png) [@Checa](https://precice.discourse.group/u/Checa)\
**Post date:** [January 5, 2026, 7:41pm UTC](https://precice.discourse.group/t/minimal-deformation-in-the-event-of-100kg-tnt-explosion/2700/1 "2026-01-05T19:41:09Z")

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Hello my name is Enrique,

I have been trying for a long time to successfully couple Blastfoam (a compressible gas solver based on OpenFOAM) with CalculiX to study the deformation of a building in the event of a 100 kg TNT explosion. I have managed to run the coupled simulation successfully without errors, but I don’t understand why the building’s deformation is almost negligible (on the order of 10^-4 m), which is impossible. I also noticed that the velocity UUU is very low, around 2/20 when it should be in the order of hundreds or a few thousand. I am completely lost and I am in a hurry. Any help would be greatly appreciated.

I added all the folder and the precice configuration.

Thank you in advance.

[preciceDict.txt](https://precice.discourse.group/uploads/short-url/286CcigFKW67oxZZtkphVb5oFX.txt) (491 Bytes)

[BuildingForce.zip](https://precice.discourse.group/uploads/short-url/cI59KUhJbPU2jwFT3GizseiqcZo.zip) (154.8 KB)

[precice-config.xml](https://precice.discourse.group/uploads/short-url/yPLF4tyyya6IWOlGa91NC3xKFjE.xml) (2.0 KB)

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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:** [January 16, 2026, 10:17am UTC](https://precice.discourse.group/t/minimal-deformation-in-the-event-of-100kg-tnt-explosion/2700/2 "2026-01-16T10:17:15Z")

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Hi @Checa,

could you please add the screen log of the solver?

Blastfoam is probably using a modified version of the adapter, and I guess is based on OpenFOAM 9. OpenFOAM 9 is currently not supported, but we plan to support it again. See the compatibility notes:

> **[OpenFOAM support](https://precice.org/adapter-openfoam-support.html)**
>
> Recent OpenFOAM.com versions work out-of-the-box. Recent OpenFOAM.org versions are also supported, but you will need a version-specific branch.

With that said, I assume that something is incomplete in the `FSI/Force.C` file. If you add the `forces` function object, and you enable [exports in preCICE](https://precice.org/configuration-export.html), do you get similar force values?