Hi there !

Today we will be laying out the steps for setting up openFOAM environment in Windows sytem using the power of WSL.

To install OpenFOAM 9 (.org) and OpenFOAM v2412 (.com) on Windows using the Windows Subsystem for Linux (WSL), follow these step-by-step instructions.

Phase 1: Prepare Windows and Install WSL

Before installing OpenFOAM, you must enable the necessary Windows features and install a Linux distribution.

1. Enable Windows Features: Open “Turn Windows features on or off” in your Windows search bar.
2. Select Required Components: Ensure that “Virtual Machine Platform” and “Windows Subsystem for Linux” are both checked.
3. Restart Your System: Click OK and restart your computer when prompted.
4. Install Ubuntu via PowerShell:
   • Open Windows PowerShell as an Administrator.
   • Run the command: wsl –install to begin the installation of Ubuntu (typically version 22.04).
   • Restart again if prompted by the terminal.
5. Set Up Ubuntu: Launch the Ubuntu app. You will be asked to create a username and password. Choose a simple password you will remember, as it will not be visible when you type it into the terminal.

Phase 2: Install OpenFOAM 9 (Foundation Version)

1. Open your Ubuntu terminal and execute the following commands to install the Foundation version of OpenFOAM.
2. Add GPG Key: Add the public key for the repository to enable package verification: sudo sh -c "wget -O - https://dl.openfoam.org/gpg.key > /etc/apt/trusted.gpg.d/openfoam.asc".
3. Add the Repository: Add the OpenFOAM software repository: sudo add-apt-repository http://dl.openfoam.org/ubuntu.
4. Update Package List: Update your system’s package list to include the new repository: sudo apt-get update.
5. Install OpenFOAM 9: Run the installation command: sudo apt-get -y install openfoam9.

Note: If you encounter dependency errors regarding csh, enable the universe repository first: sudo apt-add-repository universe followed by sudo apt-get update.

Phase 3: Install OpenFOAM v2412 (ESI Version)

The ESI version has a slightly different setup process. You can perform this in the same Ubuntu terminal.

1. Set Up the Repository: Use the curl command to add the official ESI repository: curl -s https://dl.openfoam.com/add-debian-repo.sh | sudo bash.
2. Update the Repository: Refresh your package list: sudo apt-get update.
3. Install OpenFOAM v2412: Install the default version, which includes tutorials: sudo apt-get install openfoam2412-default.

Note: Using the -default suffix ensures you get the full version with tutorials and documentation.

Phase 4: User Configuration (Setting Up Aliases)

Because you have two versions installed, you should use “aliases” to switch between them easily. Otherwise, they may conflict in your .bashrc file.

1. Install a Text Editor: If you don’t have one, install gedit: sudo apt-get install gedit.
2. Open .bashrc: Open the configuration file in your home directory: gedit ~/.bashrc.
3. Add Version Aliases: Scroll to the very bottom of the file and add these lines:
   • For OpenFOAM 9: alias of9='source /opt/openfoam9/etc/bashrc'.
   • For OpenFOAM v2412: alias of2412='source /usr/lib/openfoam/openfoam2412/etc/bashrc'.
4. Save and Refresh: Save the file and close the editor. In the terminal, run: source ~/.bashrc.

Phase 5: Verification and Running a Test Case

To ensure everything is working, run a basic simulation for each version.

1. Activate the Version: Type of9 or of2412 in your terminal to source the specific version you want to use.
2. Create a Run Directory: Create a project folder to avoid modifying system files: mkdir -p $FOAM_RUN run.
3. Copy a Tutorial: Copy the pitzDaily incompressible flow example: cp -r $FOAM_TUTORIALS/incompressible/simpleFoam/pitzDaily ..
4. Run the Simulation:
   • Enter the directory: cd pitzDaily.
   • Generate the mesh: blockMesh.
   • Run the solver: simpleFoam.
5. Visualize Results: Type paraFoam to open the results in ParaView. If paraFoam fails, you can install ParaView manually using sudo apt-get install paraview.