Ansys Fluent¶
Getting started with Ansys Fluent¶
If you have no previous experience with Ansys Fluent, we recommend that you first learn about the software on your own computer before trying it out on DelftBlue. You are also expected to have some background in fluid mechanics and Computational Fluid Dynamics. To get started with Fluent, for instance try the tutorials from Cornell University. You have to register but it is free of charge.
It is most efficient to do the tutorials locally, on your own desktop or laptop. Ansys Fluent can be downloaded from BrightSpace.
An example on DelftBlue¶
To show how a case can be run in the queue on DelftBlue, here is an example that simulates the 2D instationary, incompressible flow around a square cylinder. To download the input files to a folder on DelftBlue, type
wget https://doc.dhpc.tudelft.nl/delftblue/howtos/fluent/cyl.cas.gz
wget https://doc.dhpc.tudelft.nl/delftblue/howtos/fluent/cyl.dat.gz
Store the fluent parameters in a file to be read by fluent:
cylinder.script
And here is the slurm jobscript:
/file/set-batch-options
;Do you want to confirm file overwrite [yes] no
no
;Do you want to exit on error? [no]
yes
;Do you want to hide questions? [no]
no
; Read case file
rcd cyl.cas.gz
; Initialize the solution
; /solve/initialize/initialize-flow
; Calculate 50 iterations
;it 10
; the following for time-dependent
/solve/set/time-step
0.5
/solve/dual-time-iterate
; Number of physical time steps [1]
10
; Number of iterations per time step [10]
20
; Write data file
wcd cyl.cas.gz
; Exit FLUENT
exit
yes
cylinder.slurm
#!/bin/bash -l
# use bash as shell
# the -l option is necessary to make the local enviroment equal to the login environment
# slurm commands start with #SBATCH
# all other stuff behind a # on the same line is comment
#SBATCH -D ./ # directory where the mpiexec command is ran
#SBATCH -J mytest # name of the job (can be changed to whichever name you like)
#SBATCH --get-user-env # to set environment variables
#SBATCH -o output.log # output file
#SBATCH -e output.log # error file
#SBATCH --mem-per-cpu=1GB # memory per node in megabytes
#SBATCH --time=0-00:10:00 # simulation time in d-hh:mm:ss
#SBATCH --nodes=1 # number of nodes
#SBATCH --ntasks-per-node=2 # number of MPI processes on the node (^= cores to be used)
#SBATCH --account=innovation # replace with your education/research/project account if applicable
# get the jobid for later reference
myjobid=$SLURM_JOB_ID
echo "myjobid = " $myjobid
# load modules
module load ansys/2021R2
if [ "$SLURM_PROCID" == "0" ]; then
# set up hostfile containing the list of nodes/cores used
scontrol show hostname $SLURM_JOB_NODELIST > hostfile.txt
fluent 2ddp -t$SLURM_NTASKS -rsh -g -i cylinder.script -cnf=hostfile.txt -pib.ofed
fi
exit 0
The job is submitted by typing
Warning
Fluent runs either on part of one node, or on a number of complete nodes. The number of nodes needs to be specified, just specifying the number of cores or tasks does not work, at least for fluent versions 2023 and lower.
When the job is finished, output will look something like this:
/apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/bin/fluent -r21.2.0 2ddp -pinfiniband -host -t4 -mpi=intel -cnf=hostfile.txt -path/apps/generic/ansys/2021R2/v212/fluent -cx cmp198.delftblue.tudelft.net:33583:45535
Starting /apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/lnamd64/2ddp_host/fluent.21.2.0 host -cx cmp198.delftblue.tudelft.net:33583:45535 "(list (rpsetvar (QUOTE parallel/function) "fluent 2ddp -flux -node -r21.2.0 -t4 -pinfiniband -mpi=intel -cnf=hostfile.txt ") (rpsetvar (QUOTE parallel/rhost) "") (rpsetvar (QUOTE parallel/ruser) "") (rpsetvar (QUOTE parallel/nprocs_string) "4") (rpsetvar (QUOTE parallel/auto-spawn?) #t) (rpsetvar (QUOTE parallel/trace-level) 0) (rpsetvar (QUOTE parallel/remote-shell) 0) (rpsetvar (QUOTE parallel/path) "/apps/generic/ansys/2021R2/v212/fluent") (rpsetvar (QUOTE parallel/hostsfile) "hostfile.txt") )"
Welcome to ANSYS Fluent 2021 R2.1
Copyright 1987-2021 ANSYS, Inc. All Rights Reserved.
Unauthorized use, distribution or duplication is prohibited.
This product is subject to U.S. laws governing export and re-export.
For full Legal Notice, see documentation.
Build Time: Aug 23 2021 10:52:28 EDT Build Id: 10202
--------------------------------------------------------------
This is an academic version of ANSYS FLUENT. Usage of this product
license is limited to the terms and conditions specified in your ANSYS
license form, additional terms section.
--------------------------------------------------------------
Host spawning Node 0 on machine "cmp198" (unix).
/apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/bin/fluent -r21.2.0 2ddp -flux -node -t4 -pinfiniband -mpi=intel -cnf=hostfile.txt -mport 172.21.4.234:172.21.4.234:37837:0
Starting /apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/multiport/mpi/lnamd64/intel/bin/mpirun -f /tmp/fluent-appfile.mpourquie.1853453 --rsh=rsh -genv I_MPI_FABRICS shm:ofa -genv I_MPI_FALLBACK_DEVICE disable -genv FLUENT_ARCH lnamd64 -genv I_MPI_DEBUG 0 -genv I_MPI_ADJUST_REDUCE 2 -genv I_MPI_ADJUST_ALLREDUCE 2 -genv I_MPI_ADJUST_BCAST 1 -genv I_MPI_ADJUST_BARRIER 2 -genv I_MPI_ADJUST_ALLGATHER 2 -genv I_MPI_ADJUST_GATHER 2 -genv I_MPI_ADJUST_ALLTOALL 1 -genv I_MPI_ADJUST_SCATTER 2 -genv I_MPI_ADJUST_SCATTERV 2 -genv I_MPI_ADJUST_ALLGATHERV 2 -genv I_MPI_ADJUST_GATHERV 2 -genv I_MPI_PLATFORM auto -genv PYTHONHOME /apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/../../commonfiles/CPython/3_7/linx64/Release/python -genv FLUENT_PROD_DIR /apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0 -genv KMP_AFFINITY disabled -genv LD_PRELOAD /apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/multiport/mpi/lnamd64/intel/lib/libstrtok.so -genv TMI_CONFIG /apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/multiport/mpi/lnamd64/intel/etc/tmi.conf -machinefile /tmp/fluent-appfile.mpourquie.1853453 -np 4 /apps/generic/ansys/2021R2/v212/fluent/fluent21.2.0/lnamd64/2ddp_node/fluent_mpi.21.2.0 node -mpiw intel -pic infiniband -mport 172.21.4.234:172.21.4.234:37837:0
-------------------------------------------------------------------------------
ID Hostname Core O.S. PID Vendor
-------------------------------------------------------------------------------
n3 cmp198 4/48 Linux-64 1853626 Intel(R) Xeon(R) Gold 6248R
n2 cmp198 3/48 Linux-64 1853624 Intel(R) Xeon(R) Gold 6248R
n1 cmp198 2/48 Linux-64 1853623 Intel(R) Xeon(R) Gold 6248R
n0* cmp198 1/48 Linux-64 1853622 Intel(R) Xeon(R) Gold 6248R
host cmp198 Linux-64 1853079 Intel(R) Xeon(R) Gold 6248R
MPI Option Selected: intel
Selected system interconnect: InfiniBand
-------------------------------------------------------------------------------
Cleanup script file is /scratch/mpourquie/fluent/cylinder/example_cylinder/cleanup-fluent-cmp198-1853079.sh
Reading journal file script...
> /file/set-batch-options
Do you want to confirm file overwrite [yes] ;Do you want to confirm file overwrite [yes] no
no
Do you want to exit on error? [no] ;Do you want to exit on error? [no]
yes
Do you want to hide questions? [no] ;Do you want to hide questions? [no]
no
> ; Read case file
rcd cyl.cas.gz
sched_setaffinity() call failed: Invalid argument
sched_setaffinity() call failed: Invalid argument
sched_setaffinity() call failed: Invalid argument
sched_setaffinity() call failed: Invalid argument
Multicore processors detected. Failed setting process affinity!
Reading "\"| gunzip -c \\\"cyl.cas.gz\\\"\""...
Buffering for file scan...
24500 quadrilateral cells, zone 2, binary.
24500 cell partition ids, zone 2, 4 partitions, binary.
200 2D wall faces, zone 3, binary.
180 2D symmetry faces, zone 4, binary.
180 2D symmetry faces, zone 5, binary.
150 2D pressure-outlet faces, zone 6, binary.
150 2D velocity-inlet faces, zone 7, binary.
48570 2D interior faces, zone 9, binary.
24930 nodes, binary.
24930 node flags, binary.
Building...
mesh
distributing mesh
parts....,
faces....,
nodes....,
cells....,
bandwidth reduction using Reverse Cuthill-McKee: 6104/72 = 84.7778
materials,
interface,
domains,
mixture
zones,
default-interior
in
out
top
bot
cyl
fluid
parallel,
Done.
Reading "\"| gunzip -c \\\"cyl.dat.gz\\\"\""...
Parallel variables...
Done.
> ; Initialize the solution
; /solve/initialize/initialize-flow
; Calculate 50 iterations
;it 10
; the following for time-dependent
/solve/set/time-step
time step size (in [s]) [0.5] 0.5
> /solve/dual-time-iterate
Number of time steps [10] ; Number of physical time steps [1]
10
Maximum Number of iterations per time step [20] ; Number of iterations per time step [10]
20
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6040 1.0739e-02 4.9741e-05 4.0977e-05 0:00:00 20
6041 4.4022e-01 4.6628e-04 6.8486e-04 0:00:01 19
6042 1.3930e-01 2.7173e-04 5.6050e-04 0:00:01 18
6043 8.6056e-02 1.8863e-04 4.6205e-04 0:00:01 17
6044 9.8743e-02 1.4361e-04 3.7865e-04 0:00:01 16
6045 9.1367e-02 1.2269e-04 3.1327e-04 0:00:01 15
6046 7.9691e-02 1.1550e-04 2.6524e-04 0:00:01 14
6047 6.8285e-02 1.1114e-04 2.2719e-04 0:00:00 13
6048 5.8072e-02 1.0635e-04 1.9529e-04 0:00:00 12
6049 4.9219e-02 1.0056e-04 1.6845e-04 0:00:00 11
6050 4.2844e-02 9.4515e-05 1.4601e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6051 3.5515e-02 8.8799e-05 1.2702e-04 0:00:00 9
6052 3.1377e-02 8.2887e-05 1.1091e-04 0:00:00 8
6053 2.6588e-02 7.7657e-05 9.7076e-05 0:00:00 7
6054 2.3841e-02 7.2515e-05 8.5288e-05 0:00:00 6
6055 2.1147e-02 6.7922e-05 7.5204e-05 0:00:00 5
6056 1.8717e-02 6.3674e-05 6.6560e-05 0:00:00 4
6057 1.6575e-02 5.9656e-05 5.9162e-05 0:00:00 3
6058 1.4718e-02 5.5913e-05 5.2829e-05 0:00:00 2
6059 1.3048e-02 5.2459e-05 4.7344e-05 0:00:00 1
6060 1.1575e-02 4.9251e-05 4.2564e-05 0:00:00 0
step flow-time flow-time cl-1
349 1.7450e+02 1.7450e+02 -1.1323e-01
Flow time = 174.5s, time step = 349
9 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6060 1.1575e-02 4.9251e-05 4.2564e-05 0:00:00 20
6061 4.3598e-01 4.5699e-04 6.7440e-04 0:00:00 19
6062 1.3608e-01 2.6597e-04 5.5981e-04 0:00:00 18
6063 8.4417e-02 1.8450e-04 4.6545e-04 0:00:00 17
6064 9.7125e-02 1.4163e-04 3.8344e-04 0:00:00 16
6065 8.8841e-02 1.2166e-04 3.1770e-04 0:00:00 15
6066 7.7300e-02 1.1488e-04 2.6933e-04 0:00:00 14
6067 6.6233e-02 1.1060e-04 2.3053e-04 0:00:00 13
6068 5.6539e-02 1.0601e-04 1.9799e-04 0:00:00 12
6069 4.8847e-02 1.0008e-04 1.7077e-04 0:00:00 11
6070 4.2317e-02 9.3877e-05 1.4806e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6071 3.7722e-02 8.7760e-05 1.2899e-04 0:00:00 9
6072 3.2160e-02 8.2395e-05 1.1272e-04 0:00:00 8
6073 2.8976e-02 7.7089e-05 9.8899e-05 0:00:00 7
6074 2.4802e-02 7.2335e-05 8.7094e-05 0:00:00 6
6075 2.1640e-02 6.7748e-05 7.7002e-05 0:00:00 5
6076 1.8909e-02 6.3535e-05 6.8311e-05 0:00:00 4
6077 1.6624e-02 5.9573e-05 6.0803e-05 0:00:00 3
6078 1.4688e-02 5.5849e-05 5.4334e-05 0:00:00 2
6079 1.3018e-02 5.2409e-05 4.8748e-05 0:00:00 1
6080 1.1562e-02 4.9214e-05 4.3883e-05 0:00:00 0
step flow-time flow-time cl-1
350 1.7500e+02 1.7500e+02 3.1922e-02
Flow time = 175s, time step = 350
8 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6080 1.1562e-02 4.9214e-05 4.3883e-05 0:00:00 20
6081 4.4185e-01 4.5858e-04 6.8464e-04 0:00:00 19
6082 1.2791e-01 2.6735e-04 5.6624e-04 0:00:00 18
6083 8.2804e-02 1.8546e-04 4.6757e-04 0:00:00 17
6084 9.5362e-02 1.4250e-04 3.8519e-04 0:00:00 16
6085 8.9028e-02 1.2337e-04 3.2039e-04 0:00:00 15
6086 7.9127e-02 1.1644e-04 2.7221e-04 0:00:00 14
6087 6.8841e-02 1.1247e-04 2.3369e-04 0:00:00 13
6088 5.9340e-02 1.0792e-04 2.0124e-04 0:00:00 12
6089 5.0837e-02 1.0262e-04 1.7380e-04 0:00:00 11
6090 4.3325e-02 9.6699e-05 1.5075e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6091 3.7069e-02 9.0813e-05 1.3130e-04 0:00:00 9
6092 3.2496e-02 8.5030e-05 1.1485e-04 0:00:00 8
6093 2.7319e-02 7.9698e-05 1.0069e-04 0:00:00 7
6094 2.3495e-02 7.4607e-05 8.8578e-05 0:00:00 6
6095 2.0556e-02 6.9789e-05 7.8164e-05 0:00:00 5
6096 1.7928e-02 6.5274e-05 6.9262e-05 0:00:00 4
6097 1.5700e-02 6.1163e-05 6.1604e-05 0:00:00 3
6098 1.3841e-02 5.7403e-05 5.4960e-05 0:00:00 2
6099 1.2273e-02 5.3915e-05 4.9187e-05 0:00:00 1
6100 1.0876e-02 5.0676e-05 4.4176e-05 0:00:00 0
step flow-time flow-time cl-1
351 1.7550e+02 1.7550e+02 1.6191e-01
Flow time = 175.5s, time step = 351
7 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6100 1.0876e-02 5.0676e-05 4.4176e-05 0:00:00 20
6101 4.5542e-01 4.6769e-04 6.9965e-04 0:00:00 19
6102 1.4072e-01 2.7341e-04 5.7340e-04 0:00:00 18
6103 8.8385e-02 1.8906e-04 4.7299e-04 0:00:00 17
6104 9.9976e-02 1.4533e-04 3.8806e-04 0:00:00 16
6105 9.2049e-02 1.2623e-04 3.2118e-04 0:00:00 15
6106 8.0283e-02 1.1985e-04 2.7223e-04 0:00:00 14
6107 6.9133e-02 1.1565e-04 2.3353e-04 0:00:00 13
6108 5.9419e-02 1.1069e-04 2.0095e-04 0:00:00 12
6109 5.0915e-02 1.0499e-04 1.7366e-04 0:00:00 11
6110 4.3454e-02 9.8819e-05 1.5067e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6111 3.7948e-02 9.2438e-05 1.3120e-04 0:00:00 9
6112 3.1790e-02 8.6667e-05 1.1465e-04 0:00:00 8
6113 2.8082e-02 8.1062e-05 1.0059e-04 0:00:00 7
6114 2.4041e-02 7.6098e-05 8.8501e-05 0:00:00 6
6115 2.1648e-02 7.1195e-05 7.8171e-05 0:00:00 5
6116 1.8769e-02 6.6950e-05 6.9275e-05 0:00:00 4
6117 1.6601e-02 6.2829e-05 6.1644e-05 0:00:00 3
6118 1.5118e-02 5.8926e-05 5.5013e-05 0:00:00 2
6119 1.3070e-02 5.5509e-05 4.9200e-05 0:00:00 1
6120 1.1939e-02 5.2161e-05 4.4111e-05 0:00:00 0
step flow-time flow-time cl-1
352 1.7600e+02 1.7600e+02 2.6300e-01
Flow time = 176s, time step = 352
6 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6120 1.1939e-02 5.2161e-05 4.4111e-05 0:00:00 20
6121 4.4689e-01 4.7034e-04 7.0297e-04 0:00:00 19
6122 1.3970e-01 2.7854e-04 5.7244e-04 0:00:00 18
6123 8.6271e-02 1.9628e-04 4.7097e-04 0:00:00 17
6124 1.0076e-01 1.5210e-04 3.8747e-04 0:00:00 16
6125 9.3483e-02 1.3107e-04 3.2142e-04 0:00:00 15
6126 8.2226e-02 1.2382e-04 2.7283e-04 0:00:00 14
6127 7.1180e-02 1.1907e-04 2.3421e-04 0:00:00 13
6128 6.1250e-02 1.1356e-04 2.0175e-04 0:00:00 12
6129 5.2593e-02 1.0711e-04 1.7407e-04 0:00:00 11
6130 4.5016e-02 1.0050e-04 1.5085e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6131 3.8660e-02 9.4037e-05 1.3131e-04 0:00:00 9
6132 3.3540e-02 8.7940e-05 1.1473e-04 0:00:00 8
6133 2.9912e-02 8.2179e-05 1.0057e-04 0:00:00 7
6134 2.5372e-02 7.7136e-05 8.8308e-05 0:00:00 6
6135 2.2416e-02 7.2153e-05 7.7813e-05 0:00:00 5
6136 1.9025e-02 6.7753e-05 6.8744e-05 0:00:00 4
6137 1.6906e-02 6.3428e-05 6.0988e-05 0:00:00 3
6138 1.4444e-02 5.9658e-05 5.4299e-05 0:00:00 2
6139 1.2953e-02 5.5969e-05 4.8580e-05 0:00:00 1
6140 1.1192e-02 5.2689e-05 4.3591e-05 0:00:00 0
step flow-time flow-time cl-1
353 1.7650e+02 1.7650e+02 3.3116e-01
Flow time = 176.5s, time step = 353
5 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6140 1.1192e-02 5.2689e-05 4.3591e-05 0:00:00 20
6141 4.5126e-01 4.7373e-04 7.0067e-04 0:00:00 19
6142 1.4186e-01 2.8280e-04 5.7119e-04 0:00:00 18
6143 9.0156e-02 1.9743e-04 4.6909e-04 0:00:00 17
6144 1.0073e-01 1.5233e-04 3.8446e-04 0:00:00 16
6145 9.2198e-02 1.3187e-04 3.1895e-04 0:00:00 15
6146 8.0071e-02 1.2470e-04 2.7049e-04 0:00:00 14
6147 6.9238e-02 1.1947e-04 2.3180e-04 0:00:00 13
6148 5.8916e-02 1.1357e-04 1.9900e-04 0:00:00 12
6149 5.0756e-02 1.0707e-04 1.7125e-04 0:00:00 11
6150 4.3751e-02 1.0068e-04 1.4807e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6151 3.8019e-02 9.4277e-05 1.2859e-04 0:00:00 9
6152 3.4020e-02 8.7947e-05 1.1210e-04 0:00:00 8
6153 2.9161e-02 8.2253e-05 9.8023e-05 0:00:00 7
6154 2.6320e-02 7.6841e-05 8.6076e-05 0:00:00 6
6155 2.2789e-02 7.1953e-05 7.5804e-05 0:00:00 5
6156 2.0619e-02 6.7248e-05 6.7089e-05 0:00:00 4
6157 1.8262e-02 6.3024e-05 5.9562e-05 0:00:00 3
6158 1.6106e-02 5.9205e-05 5.3072e-05 0:00:00 2
6159 1.4229e-02 5.5651e-05 4.7452e-05 0:00:00 1
6160 1.2584e-02 5.2354e-05 4.2552e-05 0:00:00 0
step flow-time flow-time cl-1
354 1.7700e+02 1.7700e+02 3.5418e-01
Flow time = 177s, time step = 354
4 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6160 1.2584e-02 5.2354e-05 4.2552e-05 0:00:00 20
6161 4.4181e-01 4.7689e-04 6.8947e-04 0:00:00 19
6162 1.3635e-01 2.8400e-04 5.6274e-04 0:00:00 18
6163 8.5765e-02 1.9929e-04 4.6276e-04 0:00:00 17
6164 9.8687e-02 1.5344e-04 3.7968e-04 0:00:00 16
6165 9.0865e-02 1.3131e-04 3.1360e-04 0:00:00 15
6166 7.9235e-02 1.2300e-04 2.6559e-04 0:00:00 14
6167 6.7841e-02 1.1768e-04 2.2763e-04 0:00:00 13
6168 5.8054e-02 1.1220e-04 1.9594e-04 0:00:00 12
6169 4.9769e-02 1.0567e-04 1.6926e-04 0:00:00 11
6170 4.2583e-02 9.8786e-05 1.4686e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6171 3.7057e-02 9.2081e-05 1.2804e-04 0:00:00 9
6172 3.0790e-02 8.6124e-05 1.1193e-04 0:00:00 8
6173 2.7107e-02 8.0319e-05 9.8277e-05 0:00:00 7
6174 2.2963e-02 7.5116e-05 8.6536e-05 0:00:00 6
6175 2.0585e-02 7.0183e-05 7.6453e-05 0:00:00 5
6176 1.7630e-02 6.5807e-05 6.7703e-05 0:00:00 4
6177 1.5974e-02 6.1642e-05 6.0135e-05 0:00:00 3
6178 1.3750e-02 5.7855e-05 5.3492e-05 0:00:00 2
6179 1.2465e-02 5.4273e-05 4.7688e-05 0:00:00 1
6180 1.0775e-02 5.1001e-05 4.2611e-05 0:00:00 0
step flow-time flow-time cl-1
355 1.7750e+02 1.7750e+02 3.2136e-01
Flow time = 177.5s, time step = 355
3 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6180 1.0775e-02 5.1001e-05 4.2611e-05 0:00:00 20
6181 4.3761e-01 4.7247e-04 6.8161e-04 0:00:00 19
6182 1.3813e-01 2.7891e-04 5.6349e-04 0:00:00 18
6183 8.6180e-02 1.9355e-04 4.6637e-04 0:00:00 17
6184 9.7017e-02 1.4786e-04 3.8313e-04 0:00:00 16
6185 8.9132e-02 1.2676e-04 3.1697e-04 0:00:00 15
6186 7.8345e-02 1.1900e-04 2.6855e-04 0:00:00 14
6187 6.7627e-02 1.1410e-04 2.2992e-04 0:00:00 13
6188 5.8249e-02 1.0856e-04 1.9728e-04 0:00:00 12
6189 5.0356e-02 1.0268e-04 1.6977e-04 0:00:00 11
6190 4.3649e-02 9.6678e-05 1.4651e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6191 3.7887e-02 9.0557e-05 1.2687e-04 0:00:00 9
6192 3.3583e-02 8.4397e-05 1.1036e-04 0:00:00 8
6193 2.8223e-02 7.8854e-05 9.6262e-05 0:00:00 7
6194 2.4171e-02 7.3650e-05 8.4256e-05 0:00:00 6
6195 2.1408e-02 6.8821e-05 7.4084e-05 0:00:00 5
6196 1.8052e-02 6.4432e-05 6.5303e-05 0:00:00 4
6197 1.5580e-02 6.0318e-05 5.7797e-05 0:00:00 3
6198 1.3579e-02 5.6476e-05 5.1389e-05 0:00:00 2
6199 1.1956e-02 5.2922e-05 4.5867e-05 0:00:00 1
6200 1.0603e-02 4.9653e-05 4.1086e-05 0:00:00 0
step flow-time flow-time cl-1
356 1.7800e+02 1.7800e+02 2.3147e-01
Flow time = 178s, time step = 356
2 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6200 1.0603e-02 4.9653e-05 4.1086e-05 0:00:00 20
6201 4.3902e-01 4.6484e-04 6.8444e-04 0:00:00 19
6202 1.3988e-01 2.7045e-04 5.6075e-04 0:00:00 18
6203 8.6002e-02 1.8732e-04 4.6176e-04 0:00:00 17
6204 9.8770e-02 1.4281e-04 3.7814e-04 0:00:00 16
6205 9.1282e-02 1.2259e-04 3.1285e-04 0:00:00 15
6206 7.9524e-02 1.1520e-04 2.6503e-04 0:00:00 14
6207 6.7943e-02 1.1105e-04 2.2720e-04 0:00:00 13
6208 5.7669e-02 1.0634e-04 1.9546e-04 0:00:00 12
6209 4.9105e-02 1.0065e-04 1.6875e-04 0:00:00 11
6210 4.3105e-02 9.4628e-05 1.4642e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6211 3.6039e-02 8.8903e-05 1.2741e-04 0:00:00 9
6212 3.2003e-02 8.3165e-05 1.1123e-04 0:00:00 8
6213 2.7160e-02 7.7910e-05 9.7335e-05 0:00:00 7
6214 2.4314e-02 7.2869e-05 8.5494e-05 0:00:00 6
6215 2.0867e-02 6.8229e-05 7.5330e-05 0:00:00 5
6216 1.8850e-02 6.3822e-05 6.6721e-05 0:00:00 4
6217 1.6231e-02 5.9805e-05 5.9381e-05 0:00:00 3
6218 1.4628e-02 5.6045e-05 5.3039e-05 0:00:00 2
6219 1.2613e-02 5.2636e-05 4.7546e-05 0:00:00 1
6220 1.1363e-02 4.9423e-05 4.2746e-05 0:00:00 0
step flow-time flow-time cl-1
357 1.7850e+02 1.7850e+02 9.9051e-02
Flow time = 178.5s, time step = 357
1 more time step
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
6220 1.1363e-02 4.9423e-05 4.2746e-05 0:00:00 20
6221 4.3709e-01 4.5743e-04 6.7428e-04 0:00:00 19
6222 1.3609e-01 2.6571e-04 5.6060e-04 0:00:00 18
6223 8.5103e-02 1.8499e-04 4.6684e-04 0:00:00 17
6224 9.7094e-02 1.4185e-04 3.8421e-04 0:00:00 16
6225 8.8804e-02 1.2161e-04 3.1836e-04 0:00:00 15
6226 7.7200e-02 1.1493e-04 2.6953e-04 0:00:00 14
6227 6.6175e-02 1.1068e-04 2.3081e-04 0:00:00 13
6228 5.8730e-02 1.0552e-04 1.9844e-04 0:00:00 12
6229 4.9693e-02 1.0006e-04 1.7116e-04 0:00:00 11
6230 4.4315e-02 9.3947e-05 1.4839e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
6231 3.8599e-02 8.8141e-05 1.2925e-04 0:00:00 9
6232 3.2502e-02 8.2764e-05 1.1291e-04 0:00:00 8
6233 2.9164e-02 7.7347e-05 9.9054e-05 0:00:00 7
6234 2.4849e-02 7.2511e-05 8.7200e-05 0:00:00 6
6235 2.1666e-02 6.7810e-05 7.7073e-05 0:00:00 5
6236 1.9532e-02 6.3446e-05 6.8439e-05 0:00:00 4
6237 1.6722e-02 5.9643e-05 6.0998e-05 0:00:00 3
6238 1.5135e-02 5.5910e-05 5.4581e-05 0:00:00 2
6239 1.3085e-02 5.2621e-05 4.8983e-05 0:00:00 1
6240 1.1894e-02 4.9366e-05 4.4067e-05 0:00:00 0
step flow-time flow-time cl-1
358 1.7900e+02 1.7900e+02 -4.6862e-02
Flow time = 179s, time step = 358
>
adjoint/ mesh/ report/
define/ parallel/ server/
display/ plot/ solve/
exit preferences/ surface/
file/ print-license-usage views/
> ; Write data file
wcd cyl.cas.gz
Writing "| gzip -2cfv > \"cyl.cas.gz\""...
24500 quadrilateral cells, zone 2, binary.
24500 cell partition ids, zone 2, 4 partitions, binary.
200 2D wall faces, zone 3, binary.
180 2D symmetry faces, zone 4, binary.
180 2D symmetry faces, zone 5, binary.
150 2D pressure-outlet faces, zone 6, binary.
150 2D velocity-inlet faces, zone 7, binary.
48570 2D interior faces, zone 9, binary.
24930 nodes, binary.
24930 node flags, binary.
75.1%
Done.
Writing "| gzip -2cfv > \"cyl.dat.gz\""...
35.7%
Done.
> ; Exit FLUENT
exit
You can see that several actions are taken:
- the case and data file are read;
- a number of time-steps is taken, for each time-step a number of iterations are performed;
- at the end of the job, case and data are written.
Some rules of thumb for memory (RAM) and core usage¶
- fluent uses between 2-5GB of total RAM per million grid points. Take this into account when you determine how much RAM your job needs.
- fluent may run faster on more cores, but note that when you calculate on more nodes the cores also need to communicate more with each other. You will note that when you keep increasing the number of cores, after a certain amount of cores the model hardly goes faster; it may even become slower if the communication costs start to dominate! It is recommended to have at least between 50.000 and 100.000 grid points per core (it depends on the kind of solver) so that the communication costs do not dominate over the calculation costs. It is recommended to try out (for instance) using 1 core, 2cores, 4 cores etc and then see how many cores still make sense. The result may look like this:
|
time |
cores |
|---|---|
|
120 |
1 |
|
60.5 |
2 |
|
32 |
4 |
|
19 |
8 |
|
18 |
16 |
As you see in the table, going from 8 to 16 cores hardly makes a difference in time. To avoid longer queueing and wasting resources, pick the "sweet spot" you find in such a scaling experiment for your production runs (i.e., 8 cores in this example).
Working interactively¶
If you have to work with the graphical frontend, you can do so on the visual nodes of DelftBlue. Follow these instructions to start an interactive session with graphics support.