{"id":764,"date":"2018-11-07T10:55:10","date_gmt":"2018-11-07T10:55:10","guid":{"rendered":"http:\/\/ri.itservices.manchester.ac.uk\/csf3\/?page_id=764"},"modified":"2026-02-18T14:22:00","modified_gmt":"2026-02-18T14:22:00","slug":"cfx","status":"publish","type":"page","link":"https:\/\/ri.itservices.manchester.ac.uk\/csf3\/software\/applications\/cfx\/","title":{"rendered":"CFX"},"content":{"rendered":"

Overview<\/h2>\n

CFX<\/a> is another general purpose computational fluid dynamics (CFD) software tool by ANSYS.<\/p>\n

Restrictions on use<\/h2>\n

CFX is installed alongside ANSYS Fluent. You will need to be in the fluent<\/code> unix group to access it. Only MACE users may be added to the fluent group.<\/p>\n

Set up procedure<\/h2>\n

You must load one<\/em> of the following ANSYS modulefiles to access CFX. Several versions are available:<\/p>\n

\r\nmodule load apps\/binapps\/ansys\/2024R2          # Max job size: 32 cores\r\nmodule load apps\/binapps\/ansys\/2023R1          # Max job size: 32 cores\r\nmodule load apps\/binapps\/ansys\/2021R1:         # Max job size: 32 cores\r\n\r\n# Legacy Module files. May not work in CSF3 with Slurm:\r\nmodule load apps\/binapps\/cfx\/19.2\r\nmodule load apps\/binapps\/cfx\/18.1\r\n<\/pre>\n
If you wish to compile your own user-defined routines (e.g., a fortran .F file to be compiled in to your simulation), you should also load one of the Intel Compiler modulefiles. For example:<\/p>\n
\r\nmodule load compilers\/intel\/17.0.7\r\n<\/pre>\n
See the CSF Intel Compiler page<\/a> for more details of available versions.<\/p>\n
Running the application<\/h2>\n
Please do not run CFX on the login node.<\/p>\n\n\n
CSF2 user should no longer use the fluent-smp.pe<\/code> parallel environment. Please see below for how to run the application on CSF3<\/td>\n<\/tr>\n<\/table>\n
Ansys CFX in serial mode<\/h3>\n
The main command to run CFX is cfx5solve<\/code>. By default cfx5solve<\/code> will run a simulation in serial mode, as in the example batch script below:<\/p>\n
\r\n#!\/bin\/bash --login\r\n#SBATCH -p serial   # Partition name is required. Serial partition runs on Intel cores\r\n#SBATCH -t 1-5      # Job \"wallclock\" limit is required. Max permitted is 7 days (7-0)\r\n                    # In this example 1-5 is 1 days and 5 hours\r\n\r\n# clean environment and load any of the ansys\/fluent modules \r\nmodule purge\r\nmodule load apps\/binapps\/ansys\/2024R2\r\n\r\n# define input .def file and output dir paths\r\nINPUT_FILE=~\/scratch\/path\/to\/input_file.def\r\nOUTPUT_DIR=~\/scratch\/path\/to\/output_dir\r\n\r\n# run cfxsolve using default serial mode. See cfx5solve -help<\/strong> for more options\r\ncfx5solve -batch -def $INPUT_FILE -fullname $OUTPUT_DIR\r\n#          |\r\n#          |-> required for batch submissions\r\n<\/pre>\n
The above simulation will only report errors in the standard slurm-jobID<\/em>.out file. Instead it will create a new file named after the OUTPUT_DIR with .out extension appended (e.g. if OUTPUT_DIR=results  it will be named results.out<\/em>). This file will report on the progress of the simulation.<\/p>\n
To submit, run sbatch jobscript<\/em><\/code>.<\/p>\n
Ansys CFX in MPI Local parallel mode <\/h3>\n
Run a parallel CFX job using MPI in one node only<\/p>\n
\r\n#!\/bin\/bash --login\r\n#SBATCH -p multicore   # Partition name is required. This gives you an AMD Genoa (168-core) node\r\n#SBATCH -n 16          # (or --ntasks=) Number of cores (2--168 on AMD), limited to 32 by ANSYS licence\r\n#SBATCH -t 1-5         # Job \"wallclock\" limit is required. Max permitted is 7 days (7-0)\r\n                       # In this example 1-5 is 1 days and 5 hours\r\n\r\n# clean environment and load any of the ansys\/fluent modules \r\nmodule purge\r\nmodule load apps\/binapps\/ansys\/2024R2\r\n\r\n# define input .def file and output dir paths\r\nINPUT_FILE=~\/scratch\/path\/to\/input_file.def\r\nOUTPUT_DIR=~\/scratch\/path\/to\/output_dir\r\n\r\n# run cfxsolve using default serial mode. See cfx5solve -help<\/strong> for more options\r\ncfx5solve -batch -def $INPUT_FILE -fullname $OUTPUT_DIR -double -start-method 'Intel MPI Local Parallel' -part $SLURM_NTASKS\r\n#          |                                             |       |                                        |-> number of cores (sim \"partitions\")\r\n#          |-> required for batch submissions            |       |-> choose Parallel method\r\n#                                                        |-> double-precision Partitioner, Interpolator and Solver\r\n#\r\n<\/pre>\n
To submit, run sbatch jobscript<\/em><\/code>.<\/p>\n
Serial batch job submission<\/h3>\n
Make sure you have your input file available on the CSF. Then write a batch submission script, for example:<\/p>\n
\r\n#!\/bin\/bash --login\r\n#$ -cwd\r\n\r\nmodule load apps\/binapps\/cfx\/19.2\r\n\r\ncfx5solve -def CombustorEDM.def\r\n<\/pre>\n
Now submit it to the batch system:<\/p>\n
\r\nqsub scriptname\r\n<\/pre>\n
replacing scriptname<\/code> with the name of your submission script.<\/p>\n
Parallel batch job submission<\/h3>\n
Make sure you have your input file available on the CSF in the directory you wish to run the job. Then create a batch submission script in that directory, for example:<\/p>\n
#!\/bin\/bash --login\r\n#$ -cwd\r\n#$ -pe smp.pe 4\r\n\r\nmodule load apps\/binapps\/cfx\/19.2\r\n\r\ncfx5solve -start-method \"$PLATMPI\" -def CombustorEDM.def -par-local -partition $NSLOTS\r\n<\/pre>\n
Notes about the script:<\/p>\n
    \n
  1. -start-method \"$PLATMPI\"<\/code> (including the quotes as shown) is important and ensures that the most suitable MPI is used.<\/li>\n
  2. -partition $NSLOTS<\/code> (no quotes needed here) is important to ensure that the number of cores requested is used.<\/li>\n
  3. Minimum number of cores for parallel CFX jobs is 2, maximum is 4. You may run more than one job at a time if there are resources available.<\/li>\n<\/ol>\n
    Now submit it to the batch system:<\/p>\n
    \r\nqsub scriptname\r\n<\/pre>\n
    replacing scriptname<\/code> with the name of your submission script.<\/p>\n
    Errors<\/h3>\n
    The SGE\/batch error output file e.g. mycfxjob.e12345<\/code> may report:<\/p>\n
    map size mismatch; abort\r\n: File exists\r\n<\/pre>\n
    several times. This is common and does not cause a problem to running jobs.<\/p>\n
    Interactive use<\/h3>\n
    Please do not run the GUI on the login node. If you require the GUI please run it via qrsh<\/code>.<\/p>\n