Installing and uninstalling FLACS

FLACS-CFD is distributed as a single installer package for Linux and Windows. This article covers system requirements, installation steps for both platforms, and uninstallation.

System requirements

Operating systems: FLACS-CFD is available on Linux and Microsoft Windows. FLACS-CFD 26.1 has been tested on Windows 11 Pro and Ubuntu 22x. Linux distributions compatible with RHEL 7 are expected to work. All operating systems are supported in 64-bit variants only. Intel IA64 (Itanium) and ARM are not supported.

Processor: AMD64/Intel 64/x64 (64-bit) CPUs are supported.

Internal memory: 4 GB or more recommended.

Hard drive capacity: 1.5 GB for the software installation and typically 100 GB for simulation data.

Graphics card: A dedicated graphics card with NVIDIA chip set and at least 2 GB of graphics memory, supporting OpenGL 3.3 or higher, is recommended. AMD or Intel integrated GPUs (e.g. Intel HD4400) will also work in many cases, but Gexcon cannot provide support for these and limitations may apply to model size and 3D rendering. Note that on Windows systems with integrated GPUs, the FLACS-CFD graphical interfaces may pre-allocate 2–3 GB of main memory (RAM).

The above requirements are recommendations only and will depend on the size and complexity of the specific simulation. Higher processing speeds and increased memory are preferable for larger computational domains and finer grids. Storing large amounts of simulation data — for example when using a small plot time step (DTPLOT) — increases the requirements for disc space.

Installing FLACS-CFD on Linux

FLACS-CFD is distributed as a .run installer file. The current release installer is named flacs-cfd-26.1-linux-64bit-installer.run.

Single-user installation

If only one person will be using FLACS-CFD, install into that user's home directory. By default, FLACS-CFD installs to /home/my_user/Gexcon.

1. Save the installation package to a convenient location.
2. Make the file executable:

chmod u+x /home/my_user/flacs-cfd-26.1-linux-64bit-installer.run

3. Run the installation programme:

/home/my_user/flacs-cfd-26.1-64bit-linux-installer.run

Follow the instructions and keep the default parameters.

System-wide installation (super user)

To install FLACS-CFD for all users on the system, root access is required.

1. Switch to the super user:

su

2. Make the installer executable:

chmod u+x /path/to/installation/flacs-cfd-26.1-linux-64bit-installer.run

3. Run the installation programme:

/path/to/installation/flacs-cfd-26.1-linux-64bit-installer.run

Follow the instructions and keep the default parameters.

Missing packages

Depending on your system, you may need to manually install the libxcb-xinput and libxcb-xinerama packages before installing FLACS-CFD. Use the appropriate command for your package manager:

• APT: sudo apt install libxcb-xinput0 libxcb-xinerama0
• Zypper: sudo zypper install libxcb-xinput0 libxcb-xinerama0
• RPM: sudo rpm -i libxcb-xinput0 libxcb-xinerama0
• Pacman: sudo pacman -S libxcb

Unattended installation on Linux

The installer can be run from the command line or a script without user interaction.

To install to the default location:

flacs-cfd-26.1-linux-64bit-installer.run install

To run fully unattended, accepting the licence terms and confirming installation:

flacs-cfd-26.1-linux-64bit-installer.run install --accept-licenses --confirm-command

To install into a different folder:

flacs-cfd-26.1-linux-64bit-installer.run install --accept-licenses --confirm-command --root=/opt/FLACS-26.1

Installing FLACS-CFD on Windows

The current release installer is named flacs-cfd-26.1-windows-64bit-installer.exe. Double-click the installer and follow the instructions, keeping the default parameters. Install the licence manager runtime if this is a first-time installation.

Installation setup wizard showing license manager runtime option checked for first time installation

Unattended installation on Windows

To install to the default location:

flacs-cfd-26.1-windows-64bit-installer.exe install

To run fully unattended:

flacs-cfd-26.1-windows-64bit-installer.exe install --accept-licenses --confirm-command

To install into a different folder:

flacs-cfd-26.1-windows-64bit-installer.exe install --accept-licenses --confirm-command --root=C:\Users\flacsuser\FLACS-26.1

Uninstalling FLACS-CFD

Multiple versions of FLACS-CFD can coexist on the same machine. Uninstalling one version does not affect others.

Linux: Run /usr/local/Gexcon/uninstall-Gexcon.sh.

Windows: Uninstall via Control Panel → Add or Remove Programmes.