To determine which processes are running on the cluster I run this command :
ps -ef| grep fluent_mpi.21.2 | grep -v -e mpiexec -e' /bin/sh'
The result was indicated in the 1st picture : the 8 processes linked to my simulation.
The processes (in the pictures 2 & 3) are from that job because the command : only returns the processes linked to the process 4117664, which corresponds to one of the processes launched by my job. There could be defunct processes from earlier problems but if it were the case, they would have been spotted by the previous command, not this one which only deals with child processes of a given process.
About my UserID, it's not abenete+, linux automatically adds a "+" when there is not enough place to print the whole name ! So, there is no influence with my userID, don't worry about that !