openfoam.md

OpenFOAM
========

##A free, open source CFD software package

Introduction
----------------
OpenFOAM is a free, open source CFD software package developed by [**OpenCFD Ltd**](http://www.openfoam.com/about)![external](../../img/external.png) at [**ESI Group**](http://www.esi-group.com/)![external](../../img/external.png) and distributed by the [**OpenFOAM Foundation **](http://www.openfoam.org/)![external](../../img/external.png). It has a large user base across most areas of engineering and science, from both commercial and academic organisations.

Homepage: <http://www.openfoam.com/>![external](../../img/external.png)

###Installed version

Currently, several version compiled by GCC/ICC compilers in single/double precision with several version of openmpi are available on Anselm.

For example syntax of available OpenFOAM module is:

&lt; openfoam/2.2.1-icc-openmpi1.6.5-DP &gt;

this means openfoam version 2.2.1 compiled by ICC compiler with openmpi1.6.5 in double precision.

Naming convection of the installed versions is following:

openfoam/&lt;>VERSION>&gt;-&lt;>COMPILER<span>&gt;-&lt;</span><span>openmpiVERSION</span><span>&gt;-&lt;</span><span>PRECISION</span><span>&gt;</span>

-   &lt;VERSION>&gt; - version of openfoam
-   &lt;COMPILER&gt; - version of used compiler
-   &lt;openmpiVERSION&gt; - version of used openmpi/impi
-   &lt;PRECISION&gt; - DP/SP – double/single precision

###Available OpenFOAM modules

To check available modules use

```bash
    $ module avail
```

In /opt/modules/modulefiles/engineering you can see installed engineering softwares:

```bash
    ------------------------------------ /opt/modules/modulefiles/engineering -------------------------------------------------------------
    ansys/14.5.x               matlab/R2013a-COM                                openfoam/2.2.1-icc-impi4.1.1.036-DP
    comsol/43b-COM             matlab/R2013a-EDU                                openfoam/2.2.1-icc-openmpi1.6.5-DP
    comsol/43b-EDU             openfoam/2.2.1-gcc481-openmpi1.6.5-DP            paraview/4.0.1-gcc481-bullxmpi1.2.4.1-osmesa10.0
    lsdyna/7.x.x               openfoam/2.2.1-gcc481-openmpi1.6.5-SP
```

For information how to use modules please [look here](../environment-and-modules/ "Environment and Modules ").

Getting Started
-------------------

To create OpenFOAM environment on ANSELM give the commands:

```bash
    $ module load openfoam/2.2.1-icc-openmpi1.6.5-DP

    $ source $FOAM_BASHRC
```

!!! Note "Note"
	Please load correct module with your requirements “compiler - GCC/ICC, precision - DP/SP”.

Create a project directory within the $HOME/OpenFOAM directory named >&lt;USER&gt;-&lt;OFversion&gt; and create a directory named run within it, e.g. by typing:

```bash
    $ mkdir -p $FOAM_RUN
```

Project directory is now available by typing:

```bash
    $ cd /home/<USER>/OpenFOAM/<USER>-<OFversion>/run
```

&lt;OFversion&gt; - for example &lt;2.2.1&gt;

or

```bash
    $ cd $FOAM_RUN
```

Copy the tutorial examples directory in the OpenFOAM distribution to the run directory:

```bash
    $ cp -r $FOAM_TUTORIALS $FOAM_RUN
```

Now you can run the first case for example incompressible laminar flow in a cavity.

Running Serial Applications
-------------------------------

Create a Bash script >test.sh

```bash
    #!/bin/bash
    module load openfoam/2.2.1-icc-openmpi1.6.5-DP
    source $FOAM_BASHRC

    # source to run functions
    . $WM_PROJECT_DIR/bin/tools/RunFunctions

    cd $FOAM_RUN/tutorials/incompressible/icoFoam/cavity

    runApplication blockMesh
    runApplication icoFoam
```

Job submission

```bash
    $ qsub -A OPEN-0-0 -q qprod -l select=1:ncpus=16,walltime=03:00:00 test.sh
```
For information about job submission please [look here](../resource-allocation-and-job-execution/job-submission-and-execution/ "Job submission").

Running applications in parallel
-------------------------------------------------
Run the second case for example external incompressible turbulent flow - case - motorBike.

First we must run serial application bockMesh and decomposePar for preparation of parallel computation.

!!! Note "Note"
	Create a Bash scrip test.sh:

```bash
    #!/bin/bash
    module load openfoam/2.2.1-icc-openmpi1.6.5-DP
    source $FOAM_BASHRC

    # source to run functions
    . $WM_PROJECT_DIR/bin/tools/RunFunctions

    cd $FOAM_RUN/tutorials/incompressible/simpleFoam/motorBike

    runApplication blockMesh
    runApplication decomposePar
```

Job submission

```bash
    $ qsub -A OPEN-0-0 -q qprod -l select=1:ncpus=16,walltime=03:00:00 test.sh
```

This job create simple block mesh and domain decomposition. Check your decomposition, and submit parallel computation:

!!! Note "Note"
	Create a PBS script testParallel.pbs:

```bash
    #!/bin/bash
    #PBS -N motorBike
    #PBS -l select=2:ncpus=16
    #PBS -l walltime=01:00:00
    #PBS -q qprod
    #PBS -A OPEN-0-0

    module load openfoam/2.2.1-icc-openmpi1.6.5-DP
    source $FOAM_BASHRC

    cd $FOAM_RUN/tutorials/incompressible/simpleFoam/motorBike

    nproc = 32

    mpirun -hostfile ${PBS_NODEFILE} -np $nproc snappyHexMesh -overwrite -parallel | tee snappyHexMesh.log

    mpirun -hostfile ${PBS_NODEFILE} -np $nproc potentialFoam -noFunctionObject-writep -parallel | tee potentialFoam.log

    mpirun -hostfile ${PBS_NODEFILE} -np $nproc simpleFoam -parallel | tee simpleFoam.log
```

nproc – number of subdomains

Job submission

```bash
    $ qsub testParallel.pbs
```
Compile your own solver
----------------------------------------

Initialize OpenFOAM environment before compiling your solver

```bash
    $ module load openfoam/2.2.1-icc-openmpi1.6.5-DP
    $ source $FOAM_BASHRC
    $ cd $FOAM_RUN/
```

Create directory applications/solvers in user directory

```bash
    $ mkdir -p applications/solvers
    $ cd applications/solvers
```

Copy icoFoam solver’s source files

```bash
    $ cp -r $FOAM_SOLVERS/incompressible/icoFoam/ My_icoFoam
    $ cd My_icoFoam
```

Rename icoFoam.C to My_icoFOAM.C

```bash
    $ mv icoFoam.C My_icoFoam.C
```

Edit >*files* file in *Make* directory:

```bash
    icoFoam.C
    EXE = $(FOAM_APPBIN)/icoFoam
```

and change to:

```bash
    My_icoFoam.C
    EXE = $(FOAM_USER_APPBIN)/My_icoFoam
```

In directory My_icoFoam give the compilation command:

```bash
    $ wmake
```

------------------------------------------------------------------------
 **Have a fun with OpenFOAM :)**