1)Edit your ~/.bashrc file and add the line: export XAUTHORITY=$HOME/.Xauthority
2)Start with “Step 5: Launching openfoam11-linux” at the following link https://openfoam.org/download/11-linux/ However, when you get to the last line that launches “openfoam11-linux” , you instead need to launch it like this: openfoam11-linux -p 510 -xhost ←-This will ensure that graphical programs get passed through and show up correctly when xforwarding. You may not need the extra flags if you are using a VNC session.
3)Once in the container, return to https://openfoam.org/download/11-linux/, and go to Step 6: Testing openfoam11-linux. This should ensure that everything is set correctly and afterward you should be ready to work with the program.