Thank you for your attention. I found out that the problem is the environment. The getenv command solved the problem but now I am stuck with parallel run.
universe = vanilla
requirements =
getenv = true
executable = /opt/Fluent.Inc/bin/fluent
arguments = 3d -g
input = /cfd/gunaydin/3d/journal_file
output = output_file
queue
Normally the "-t8" argument after the executable is enough to have parallel run but it does not work on condor.
Thanks in advance.