README.md

# Hydrogen-Real-Gas-Model

In this repository, a new real gas model for hydrogen based on the Reference Fluid Thermodynamic and Transport Properties Database (REFPROP) v10.0 is provided for the use in the simulation software OpenFOAM v2012. The model is valid in a temperature and pressure range of 150-400 K and 0.1-1000 bar, respectively. Usage beyond this range is not recommended as it may lead to unrealistic results.  

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## OpenFOAM folder structure

The figure below shows the folder structure in OpenFOAM of the relevant files for the new real gas model for hydrogen. 

<img src="OpenFOAM_folder_structure.PNG" width="800">

## Installation

For the installation of the new real gas model, the command `wmake libso` needs to be executed consecutively in the following subfolders "/mySpecie", "/myBasic", and "/field". Individual adaptations of the files "files" and "options" in the respective "/Make" folder may be required.

## Tutorial

In a tutorial case of the flow through a critical flow Venturi nozzle, the usage of the new real gas model is shown.

For the start of the simulation, do the following steps:
1. run `blockMesh && extrudeMesh` to create the mesh
2. run either:
    - `sonicFoam > log &` or 
    - `decomposePar` (default number of processors is 4) and then `mpirun -np 4 sonicFoam -parallel > log &` to run the simulation

For the post-processing, you might need to:

3. run `reconstructPar` (if your case was decomposed before) 
4. select the file "nozzle.foam" for the visualization in e. g. ParaView

The distribution of the real gas Mach number is displayed in the figure below.

<img src="CFVN.PNG" width="800">


## Acknowledgments
This work was supported through the Joint Research Project “Metrology infrastructure for high-pressure gas and liquified hydrogen flows”. This project (20IND11 MetHyInfra) has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme.