# README for Multiphase Code Repository by HZDR

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## Multiphase Code Repository by HZDR

The Multiphase Code Repository by HZDR is a software publication released by
Helmholtz-Zentrum Dresden-Rossendorf according to the FAIR principles[^1]
(Findability, Accessibility, Interoperability, and Reuseability). It contains
experimental research work for the open-source software released by
the OpenFOAM Foundation[^2]. The developments are dedicated to the numerical
simulation of multiphase flows, in particular to the multi-field two-fluid model
(Euler-Euler method).

**Acknowledgement:** OpenFOAM(R) is a registered trade mark of OpenCFD Limited,
producer and distributor of the OpenFOAM(R) software via
[www.openfoam.com](https://openfoam.com). The Multiphase Code Repository by HZDR
is not compatible with the software released by OpenCFD Limited, but is based on
the software released by the OpenFOAM Foundation via
[www.openfoam.org](https://openfoam.org).

## Highlights of the Multiphase Code Repository by HZDR

For more information refer to <https://www.hzdr.de/db/Cms?pOid=50526>.

### Baseline Model by HZDR

The _addonMultiphaseEuler_ solver with full support of the baseline
model developed by HZDR [^3] for polydisperse bubbly flows, including
configuration files and tutorials for simplified setup of cases
(Haensch et al., 2021)[^10].

### Morphology-adaptive Multifield Two-fluid Model (MultiMorph Model)

The _cipsaMultiphaseEuler_ solver featuring a morphology-adaptive modelling
approach[^5] (dispersed and resolved interfaces, Meller et al., 2021)[^11] with
an interface to the _multiphaseEuler_ framework to utilise all available
interfacial models, and configuration files and tutorials for easy setup of
cases with the MultiMorph Model.

## Installation

Refer to the [INSTALLATION.md] in the repository[^6].

## Repository Structure

The repository includes the following main directories and files:

| Directory       | Description                                                      |
|-----------------|------------------------------------------------------------------|
| applications    | additional solvers and applications                              |
| etc             | configuration files and various templates                        |
| test            | modified test/tutorial cases from release to check functionality |
| testAddon       | additional test cases to check functionality                     |
| testCuda        | test cases to check NVIDIA CUDA functionality                    |
| tutorials       | modified demonstration cases from release                        |
| tutorialsAddon  | additional demonstration cases                                   |
| tutorialsCuda   | demonstration cases using NVIDIA CUDA                            |
| src             | additional source code                                           |
| .editorconfig   | editor configuration[^8] for code style                          |
| codemeta.json   | software metadata[^9]                                            |
| CONTRIBUTING.md | how to contribute to the project                                 |
| INSTALLATION.md | detailed installation instructions                               |
| LICENSE         | licensing information                                            |

## How to cite us?

When using the Multiphase Code Repository by HZDR cite as

>>>
Schlegel et al. (2026). Multiphase Code Repository by HZDR for OpenFOAM
Foundation Software. Rodare. <https://doi.org/10.14278/rodare.767>.
>>>

## Links and References

[^1]: <https://www.go-fair.org/fair-principles>
[^2]: <http://www.openfoam.org>
[^3]: <https://www.hzdr.de/db/Cms?pOid=50671>
[^5]: <https://hzdr.de/multimorph>
[^6]: <https://codebase.helmholtz.cloud/fwdc/multiphase/code>
[^8]: <https://editorconfig.org>
[^9]: <https://codemeta.github.io>
[^10]: Haensch, S., Evdokimov, I., Schlegel, F., & Lucas, D. (2021). A workflow for the sustainable development of closure models for bubbly flows. Chemical Engineering Science, 116807.
[^11]: Meller, R., Schlegel, F., & Lucas, D. (2021). Basic verification of a numerical framework applied to a morphology adaptive multifield two-fluid model considering bubble motions. International Journal for Numerical Methods in Fluids, 93(3), 748-773.