Simply untar the downloaded file and extract it anywhere on your filesystem. Inside the bin directory you will find a run_zCFD script that is the most straightforward way of running the code:
/INSTALL_LOCATION/bin/run_zCFD --ntask $NTASK -p $PROBLEM_NAME -c $CASE_NAME
See the documentation for more detailed instructions on running the code.
zCFD requires a license file to run. If you do not already have a license please contact firstname.lastname@example.org to obtain one. The license file provided can be placed in the same directory alongside the input files, in the lic directory within the zCFD installation or else its location can be defined using the environment variable RLM_LICENSE.
In the case that the system running the simulation cannot access the internet a local license server will be required.