Last modified: September 01 2021.
Contact: hpchelp [at]


Steps for preparing and submitting your job

  1. Case and Data files
  2. Transfer your case and data files to your /home or /scratch directory. If you are generating large data (> 10GB), please use /scratch.
  3. Journal File e.g. journal.jou
  4. A "journal file" is needed to execute fluent commands in the batch mode. e.g.
    rcd case_and_data
    /solve/dual-time-iterate 240000 50
    wcd output
    exit ok
    This journal file will read case_and_data.cas and case_and_data.dat. it will runa dual time iteration with 50 iteration per time-step for 240000 time-steps. It will write the output in "output".
    Following summarizes the fluent command line arguments:
    • 2ddp: Run a 2D simulation in double precision(remove dp to run in single precesion)
    • -g: Run Fluent without the GUI
    • -ssh: Use ssh to login to the available nodes(-rsh is default)
    • -pinfiniband: Use infiniband interconnect
    • -cnf=$PBS_NODEFILE: the list of nodes allocated to the PBS job is also provided to fluent solver.
    • &> : Redirect the Fluent output & error information to "log" file.
    • -mpi=intel: specifies the type of MPI (intel,mpich2,openmpi are currently supported on IITD HPC). Please load appropriate mpi module as per specified option.
  5. PBS submit file. e.g.
  6. #!/bin/bash
    #PBS -N jobname
    #PBS -P department
    #PBS -m bea
    #PBS -M $
    #PBS -l select=1:ncpus=20
    #PBS -l walltime=168:00:00
    #PBS -l fluent=1
    #PBS -l fluent_hpc=16
    #PBS -l software=ANSYS
    module load apps/fluent
    #default version is 2020R1
    module load suite/intel/parallelStudio/2020
    time -p fluent -g 2ddp -t $PBS_NTASKS -i journal.jou -ssh -mpi=intel -cnf=$PBS_NODEFILE -pinfiniband &> log
    The example submit file will request 20 cpus for 168 hours and run a "2ddp" job over infiniband interconnect using the journal file "journal.jou". It will use 1 base fluent license (fluent=1) and 16 HPC licenses (fluent_hpc=16). The base license allows a 4 process parallel job.
    For any parallel simulation, only one base license will be used. Rest need to be hpc licences. i.e #PBS -l fluent=1 allows 4 processes & #PBS -l fluent_hpc=[remaining no. of process]
  7. Job submission
  8. Submit the above job using "qsub"


  • Choose license carefully: a large job will take a long time to start!
  • Do NOT use the full path for your files inside fluent.
  • For graphical interface, please install a X11 Client
  • For transferring files, you can use a graphical tool such as winscp


There are some compatibility issues with fluent 17.2 & openmpi (-mpi=openmpi). Please carry out following modifications in PBS job script's command section:
time -p fluent -g 2ddp -t $PBS_NTASKS -i journal.jou -ssh -mpi=intel -cnf=$PBS_NODEFILE -pinfiniband &> log


  • To check the status or graph of the ansys licenses,click here

    HTML Table Cellpadding
    PBS Resources Ansys Licenses Name Description
    ansys_aa_ds AA_DS Licenses ANSYS Academic Teaching DesignSpace
    ansys_aa_mcad AA_MCAD Licenses ANSYS Academic cad interface
    ansys_aa_r_cfd AA_R_CFD Licenses ANSYS Academic Research CFD
    ansys_aa_r_et AA_R_ET Licenses ANSYS Academic Research Electronics Thermal
    ansys_aa_r_hpc AA_R_HPC Licenses ANSYS Academic Research HPC
    ansys_aa_r_me AA_R_ME Licenses ANSYS Academic Research Mechanical
    ansys_aa_t_a AA_T_A Licenses ANSYS Academic Teaching Advance
    ansys_aa_t_cfd AA_T_CFD Licenses ANSYS Academic Teaching CFD
    ansys_aunivres AUNIVRES Licenses