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.
DelftBlue-specific notes¶
- Use the latest version of Fluent, previous versions have incompatibilities with our system software (InfiniBand, SLURM, MPI)
- Alongside the
ansysmodule, also load theopenmpimodule as shown in the job script below - In case your job hangs before even starting the simulation, create the following text file in your run directory:
- In the output file you may find error messages reported by
MPI\_Init. This is a known issue and does not prevent the program from running, it seems.
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. Note that you have to create a so-called "machinefile" (or hostfile)
in order to run Fluent on the reserved nodes and cores. As these are typically different for every run,
we include a bash command-line to construct it (starting with /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
srun hostname to get the node list).
cylinder.slurm
#!/bin/bash -l
#SBATCH --job-name="fluent-cylinder" # name of the job (can be changed to whichever name you like)
#SBATCH --output="cylinder.out" # output file
#SBATCH --ntasks=4 # number of MPI processes
#SBATCH --mem-per-cpu=1GB # memory per node in megabytes
#SBATCH --time=00:10:00 # maximum run time in hh:mm:ss
#SBATCH --partition="compute"
#SBATCH --account=innovation # replace with your education/research/project account if applicable
# load modules
# Note that older versions of Fluent do not work correctly across multiple nodes on DelftBlue.
module load ansys/2024R2
# Fluent comes with it's own MPI, but we can tweak it to use ours (otherwise inter-node communication may not work or be slow)
module load 2024r1 openmpi
# set up hostfile containing the list of nodes as <hostname>:<cores>
srun hostname | sort | uniq -c | awk '{print $2 ":" $1}' | paste -s -d "\n" - > hostfile.txt
#if [ "$SLURM_PROCID" == "0" ]; then
fluent 2ddp -t$SLURM_NTASKS -g -i cylinder.script -cnf=hostfile.txt -mpi=openmpi -pinfiniband -cflush
#fi
The job is submitted by typing
When the job is finished, output will look something like this:
The following have been reloaded with a version change:
1) ansys/2021R2 => ansys/2024R2
/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/bin/fluent -r24.2.0 2ddp -t4 -g -i cylinder.script -cnf=hostfile.txt -mpi=openmpi -pinfiniband -cflush
Launching /apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/multiport/mpi_wrapper/bin/mpirun.fl --arch=lnamd64 --ic=infiniband --ic_variant= --mpi=openmpi --np=4 --rsh=ssh --prefix=/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/multiport --cflush --cnf=/home/jthies/dhpc/docs/docs/howtos/fluent/hostfile.txt /apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/multiport/mpi_wrapper/test/lnamd64/cflush node -mpiw openmpi -pic infiniband
***
*** Using locally installed OpenMPI library!
***
*** OPENMPI_ROOT=/apps/arch/2024r1/software/linux-rhel8-cascadelake/gcc-11.3.0/openmpi-4.1.6-w6w5qi5ljesbctyoojlfialbynqt25jb
***
Starting fixfiledes /apps/arch/2024r1/software/linux-rhel8-cascadelake/gcc-11.3.0/openmpi-4.1.6-w6w5qi5ljesbctyoojlfialbynqt25jb/bin/mpirun --map-by numa --mca btl self,vader,mvapi --prefix /apps/arch/2024r1/software/linux-rhel8-cascadelake/gcc-11.3.0/openmpi-4.1.6-w6w5qi5ljesbctyoojlfialbynqt25jb -x LD_LIBRARY_PATH -x KMP_AFFINITY=disabled -x FLUTE_UUID= -x FLUENT_ARCH=lnamd64 -x FLUENT_AFFINITY=0 -x FLUENT_PROD_DIR=/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0 -x FLUENT_INC=/apps/generic/ansys/2024R2/v242/fluent -x PYTHONHOME=/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/../../commonfiles/CPython/3_10/linx64/Release/python -np 2 --hostfile /tmp/fluent-appfile.jthies.2779637 /apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/multiport/mpi_wrapper/test/lnamd64/cflush node -mpiw openmpi -pic infiniband
Note: the following lengthy error messages concerning MPI_Init can be ignored
[...]
Opening input/output transcript to file "/home/jthies/dhpc/docs/docs/howtos/fluent/fluent-20241112-111655-2779857.trn".
Auto-Transcript Start Time: 11:16:55, 12 Nov 2024
/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/bin/fluent -r24.2.0 2ddp -pinfiniband -host -t4 -mpi=openmpi -cnf=/home/jthies/dhpc/docs/docs/howtos/fluent/hostfile.txt -path/apps/generic/ansys/2024R2/v242/fluent -ssh -cx cmp165.delftblue.tudelft.net:32849:40045
Starting /apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/lnamd64/2ddp_host/fluent.24.2.0 host -cx cmp165.delftblue.tudelft.net:32849:40045 "(list (rpsetvar (QUOTE parallel/function) "fluent 2ddp -flux -node -r24.2.0 -t4 -pinfiniband -mpi=openmpi -cnf=/home/jthies/dhpc/docs/docs/howtos/fluent/hostfile.txt -ssh") (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) 1) (rpsetvar (QUOTE parallel/path) "/apps/generic/ansys/2024R2/v242/fluent") (rpsetvar (QUOTE parallel/hostsfile) "/home/jthies/dhpc/docs/docs/howtos/fluent/hostfile.txt") (rpsetvar (QUOTE gpuapp/devices) ""))"
Welcome to ANSYS Fluent 2024 R2.01
Copyright 1987-2024 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: May 13 2024 11:01:44 EDT Build Id: 10192
Connected License Server List: 27002@ansys.lic.tudelft.nl
--------------------------------------------------------------
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 "cmp165" (unix).
/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/bin/fluent -r24.2.0 2ddp -flux -node -t4 -pinfiniband -mpi=openmpi -cnf=/home/jthies/dhpc/docs/docs/howtos/fluent/hostfile.txt -ssh -mport 172.21.4.201:172.21.4.201:41109:0
***
*** Using locally installed OpenMPI library!
***
*** OPENMPI_ROOT=/apps/arch/2024r1/software/linux-rhel8-cascadelake/gcc-11.3.0/openmpi-4.1.6-w6w5qi5ljesbctyoojlfialbynqt25jb
***
Starting fixfiledes /apps/arch/2024r1/software/linux-rhel8-cascadelake/gcc-11.3.0/openmpi-4.1.6-w6w5qi5ljesbctyoojlfialbynqt25jb/bin/mpirun --map-by numa --mca btl ^openib --mca pml ucx --prefix /apps/arch/2024r1/software/linux-rhel8-cascadelake/gcc-11.3.0/openmpi-4.1.6-w6w5qi5ljesbctyoojlfialbynqt25jb -x LD_LIBRARY_PATH -x KMP_AFFINITY=disabled -x FLUTE_UUID= -x FLUENT_ARCH=lnamd64 -x FLUENT_AFFINITY=0 -x FLUENT_PROD_DIR=/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0 -x FLUENT_INC=/apps/generic/ansys/2024R2/v242/fluent -x PYTHONHOME=/apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/../../commonfiles/CPython/3_10/linx64/Release/python -np 4 --hostfile /tmp/fluent-appfile.jthies.2780825 /apps/generic/ansys/2024R2/v242/fluent/fluent24.2.0/lnamd64/2ddp_node/fluent_mpi.24.2.0 node -mpiw openmpi -pic infiniband -mport 172.21.4.201:172.21.4.201:41109:0
-------------------------------------------------------------------------------
ID Hostname Core O.S. PID Vendor
-------------------------------------------------------------------------------
n3 cmp166 1/48 Linux-64 4061279 Intel(R) Xeon(R) Gold 6248R
n0-2 cmp165 3/48 Linux-64 2780982-2780984 Intel(R) Xeon(R) Gold 6248R
host cmp165 Linux-64 2780196 Intel(R) Xeon(R) Gold 6248R
MPI Option Selected: openmpi
Selected system interconnect: InfiniBand
-------------------------------------------------------------------------------
Cleanup script file is /home/jthies/dhpc/docs/docs/howtos/fluent/cleanup-fluent-cmp165-2780196.sh
+------------------------------------------------------------------+
| ANSYS Product Improvement |
| |
| ANSYS Product Improvement Program helps improve ANSYS |
| products. Participating in this program is like filling out a |
| survey. Without interrupting your work, the software reports |
| anonymous usage information such as errors, machine and |
| solver statistics, features used, etc. to ANSYS. We never |
| use the data to identify or contact you. |
| The data does NOT contain: |
| - Any personally identifiable information including names, |
| IP addresses, file names, part names, etc. |
| - Any information about your geometry or design specific |
| inputs. |
| You can stop participation at any time. To change your |
| selection go to Help >> ANSYS Product Improvement Program |
| in the GUI. |
| For more information about the ANSYS Privacy Policy, please |
| check: http://www.ansys.com/privacy |
| |
+------------------------------------------------------------------+
Reading journal file cylinder.script...
> /file/set-batch-options
Do you want to confirm 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
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 (constant or expression) (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
9040 1.0650e-02 4.9744e-05 4.1135e-05 0:00:00 20
9041 4.4018e-01 4.6574e-04 6.8561e-04 0:00:02 19
9042 1.4013e-01 2.7113e-04 5.6184e-04 0:00:02 18
9043 8.6192e-02 1.8797e-04 4.6274e-04 0:00:02 17
9044 9.9087e-02 1.4326e-04 3.7912e-04 0:00:01 16
9045 9.1432e-02 1.2275e-04 3.1349e-04 0:00:01 15
9046 7.9836e-02 1.1544e-04 2.6553e-04 0:00:01 14
9047 6.8329e-02 1.1113e-04 2.2752e-04 0:00:01 13
9048 5.7938e-02 1.0649e-04 1.9568e-04 0:00:01 12
9049 4.9132e-02 1.0067e-04 1.6896e-04 0:00:01 11
9050 4.2928e-02 9.4685e-05 1.4654e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9051 3.5756e-02 8.8959e-05 1.2750e-04 0:00:00 9
9052 3.1770e-02 8.3139e-05 1.1132e-04 0:00:00 8
9053 2.7077e-02 7.7890e-05 9.7418e-05 0:00:00 7
9054 2.3705e-02 7.2886e-05 8.5571e-05 0:00:00 6
9055 2.1414e-02 6.8211e-05 7.5444e-05 0:00:00 5
9056 1.8452e-02 6.3895e-05 6.6789e-05 0:00:00 4
9057 1.6685e-02 5.9790e-05 5.9431e-05 0:00:00 3
9058 1.4371e-02 5.6060e-05 5.3084e-05 0:00:00 2
9059 1.2957e-02 5.2589e-05 4.7582e-05 0:00:00 1
9060 1.1207e-02 4.9405e-05 4.2795e-05 0:00:00 0
step flow-time flow-time cl-1
499 2.4950e+02 2.4950e+02 1.0231e-01
Flow time = 249.5s, time step = 499
9 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9060 1.1207e-02 4.9405e-05 4.2795e-05 0:00:01 20
9061 4.3677e-01 4.5744e-04 6.7529e-04 0:00:01 19
9062 1.3685e-01 2.6568e-04 5.6080e-04 0:00:01 18
9063 8.5035e-02 1.8498e-04 4.6689e-04 0:00:01 17
9064 9.7454e-02 1.4186e-04 3.8450e-04 0:00:01 16
9065 8.8853e-02 1.2178e-04 3.1870e-04 0:00:00 15
9066 7.7389e-02 1.1493e-04 2.6997e-04 0:00:00 14
9067 6.6294e-02 1.1089e-04 2.3110e-04 0:00:00 13
9068 5.8511e-02 1.0580e-04 1.9869e-04 0:00:00 12
9069 4.9195e-02 1.0022e-04 1.7133e-04 0:00:00 11
9070 4.3857e-02 9.4036e-05 1.4860e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9071 3.7332e-02 8.8268e-05 1.2937e-04 0:00:00 9
9072 3.3257e-02 8.2633e-05 1.1314e-04 0:00:00 8
9073 2.8324e-02 7.7488e-05 9.9240e-05 0:00:00 7
9074 2.5444e-02 7.2429e-05 8.7421e-05 0:00:00 6
9075 2.1664e-02 6.7969e-05 7.7263e-05 0:00:00 5
9076 1.8958e-02 6.3643e-05 6.8558e-05 0:00:00 4
9077 1.6695e-02 5.9672e-05 6.1067e-05 0:00:00 3
9078 1.5216e-02 5.5905e-05 5.4587e-05 0:00:00 2
9079 1.3112e-02 5.2603e-05 4.8986e-05 0:00:00 1
9080 1.1932e-02 4.9361e-05 4.4083e-05 0:00:00 0
step flow-time flow-time cl-1
500 2.5000e+02 2.5000e+02 -4.3875e-02
Flow time = 250s, time step = 500
8 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9080 1.1932e-02 4.9361e-05 4.4083e-05 0:00:01 20
9081 4.4287e-01 4.5895e-04 6.8633e-04 0:00:01 19
9082 1.3777e-01 2.6736e-04 5.6574e-04 0:00:01 18
9083 8.3560e-02 1.8602e-04 4.6883e-04 0:00:01 17
9084 9.6963e-02 1.4293e-04 3.8649e-04 0:00:01 16
9085 8.9654e-02 1.2386e-04 3.2146e-04 0:00:00 15
9086 7.8963e-02 1.1690e-04 2.7307e-04 0:00:00 14
9087 6.8803e-02 1.1277e-04 2.3420e-04 0:00:00 13
9088 5.9304e-02 1.0828e-04 2.0160e-04 0:00:00 12
9089 5.0707e-02 1.0296e-04 1.7421e-04 0:00:00 11
9090 4.3171e-02 9.7228e-05 1.5120e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9091 3.6669e-02 9.1353e-05 1.3168e-04 0:00:00 9
9092 3.1502e-02 8.5569e-05 1.1504e-04 0:00:00 8
9093 2.7277e-02 8.0039e-05 1.0085e-04 0:00:00 7
9094 2.3674e-02 7.4891e-05 8.8712e-05 0:00:00 6
9095 2.0590e-02 7.0013e-05 7.8323e-05 0:00:00 5
9096 1.8029e-02 6.5520e-05 6.9441e-05 0:00:00 4
9097 1.5841e-02 6.1425e-05 6.1758e-05 0:00:00 3
9098 1.3964e-02 5.7645e-05 5.5096e-05 0:00:00 2
9099 1.2316e-02 5.4140e-05 4.9303e-05 0:00:00 1
9100 1.0902e-02 5.0907e-05 4.4278e-05 0:00:00 0
step flow-time flow-time cl-1
501 2.5050e+02 2.5050e+02 -1.7147e-01
Flow time = 250.5s, time step = 501
7 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9100 1.0902e-02 5.0907e-05 4.4278e-05 0:00:01 20
9101 4.5614e-01 4.6870e-04 7.0075e-04 0:00:01 19
9102 1.4063e-01 2.7295e-04 5.7397e-04 0:00:01 18
9103 8.8695e-02 1.8941e-04 4.7343e-04 0:00:01 17
9104 1.0044e-01 1.4607e-04 3.8854e-04 0:00:01 16
9105 9.2001e-02 1.2704e-04 3.2184e-04 0:00:00 15
9106 8.0320e-02 1.2037e-04 2.7296e-04 0:00:00 14
9107 6.9140e-02 1.1586e-04 2.3399e-04 0:00:00 13
9108 5.9202e-02 1.1091e-04 2.0134e-04 0:00:00 12
9109 5.0645e-02 1.0519e-04 1.7405e-04 0:00:00 11
9110 4.4345e-02 9.8860e-05 1.5114e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9111 3.6731e-02 9.2864e-05 1.3160e-04 0:00:00 9
9112 3.2387e-02 8.6836e-05 1.1505e-04 0:00:00 8
9113 2.7846e-02 8.1412e-05 1.0090e-04 0:00:00 7
9114 2.4534e-02 7.6285e-05 8.8794e-05 0:00:00 6
9115 2.1760e-02 7.1492e-05 7.8424e-05 0:00:00 5
9116 1.9219e-02 6.7092e-05 6.9552e-05 0:00:00 4
9117 1.7377e-02 6.2918e-05 6.1889e-05 0:00:00 3
9118 1.4968e-02 5.9176e-05 5.5194e-05 0:00:00 2
9119 1.3571e-02 5.5635e-05 4.9354e-05 0:00:00 1
9120 1.1800e-02 5.2402e-05 4.4205e-05 0:00:00 0
step flow-time flow-time cl-1
502 2.5100e+02 2.5100e+02 -2.6970e-01
Flow time = 251s, time step = 502
6 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9120 1.1800e-02 5.2402e-05 4.4205e-05 0:00:01 20
9121 4.4819e-01 4.7066e-04 7.0363e-04 0:00:01 19
9122 1.4046e-01 2.7859e-04 5.7254e-04 0:00:01 18
9123 8.7158e-02 1.9635e-04 4.7184e-04 0:00:01 17
9124 1.0165e-01 1.5250e-04 3.8839e-04 0:00:01 16
9125 9.4285e-02 1.3150e-04 3.2208e-04 0:00:00 15
9126 8.2834e-02 1.2419e-04 2.7321e-04 0:00:00 14
9127 7.1402e-02 1.1915e-04 2.3427e-04 0:00:01 13
9128 6.1269e-02 1.1358e-04 2.0154e-04 0:00:01 12
9129 5.2554e-02 1.0709e-04 1.7397e-04 0:00:01 11
9130 4.5030e-02 1.0056e-04 1.5088e-04 0:00:01 10
iter continuity x-velocity y-velocity time/iter
9131 3.8865e-02 9.4187e-05 1.3136e-04 0:00:01 9
9132 3.3743e-02 8.8099e-05 1.1471e-04 0:00:00 8
9133 2.9276e-02 8.2449e-05 1.0045e-04 0:00:00 7
9134 2.5403e-02 7.7149e-05 8.8182e-05 0:00:00 6
9135 2.1965e-02 7.2212e-05 7.7664e-05 0:00:00 5
9136 1.9005e-02 6.7677e-05 6.8642e-05 0:00:00 4
9137 1.6563e-02 6.3495e-05 6.0937e-05 0:00:00 3
9138 1.4490e-02 5.9615e-05 5.4317e-05 0:00:00 2
9139 1.3039e-02 5.5996e-05 4.8610e-05 0:00:00 1
9140 1.1295e-02 5.2668e-05 4.3630e-05 0:00:00 0
step flow-time flow-time cl-1
503 2.5150e+02 2.5150e+02 -3.3442e-01
Flow time = 251.5s, time step = 503
5 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9140 1.1295e-02 5.2668e-05 4.3630e-05 0:00:01 20
9141 4.5292e-01 4.7437e-04 7.0141e-04 0:00:01 19
9142 1.4210e-01 2.8323e-04 5.7175e-04 0:00:01 18
9143 8.9990e-02 1.9733e-04 4.6995e-04 0:00:01 17
9144 1.0121e-01 1.5195e-04 3.8559e-04 0:00:01 16
9145 9.2416e-02 1.3164e-04 3.1999e-04 0:00:01 15
9146 8.0274e-02 1.2421e-04 2.7105e-04 0:00:00 14
9147 6.9172e-02 1.1925e-04 2.3204e-04 0:00:00 13
9148 5.9150e-02 1.1323e-04 1.9898e-04 0:00:00 12
9149 5.1021e-02 1.0690e-04 1.7125e-04 0:00:00 11
9150 4.4177e-02 1.0060e-04 1.4811e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9151 3.8382e-02 9.4168e-05 1.2861e-04 0:00:00 9
9152 3.3535e-02 8.7999e-05 1.1212e-04 0:00:00 8
9153 3.0238e-02 8.2110e-05 9.8111e-05 0:00:00 7
9154 2.6195e-02 7.6808e-05 8.6098e-05 0:00:00 6
9155 2.3564e-02 7.1772e-05 7.5941e-05 0:00:00 5
9156 2.0370e-02 6.7271e-05 6.7195e-05 0:00:00 4
9157 1.8302e-02 6.3073e-05 5.9674e-05 0:00:00 3
9158 1.6176e-02 5.9229e-05 5.3168e-05 0:00:00 2
9159 1.4224e-02 5.5670e-05 4.7485e-05 0:00:00 1
9160 1.2538e-02 5.2342e-05 4.2544e-05 0:00:00 0
step flow-time flow-time cl-1
504 2.5200e+02 2.5200e+02 -3.5280e-01
Flow time = 252s, time step = 504
4 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9160 1.2538e-02 5.2342e-05 4.2544e-05 0:00:01 20
9161 4.4323e-01 4.7682e-04 6.8975e-04 0:00:01 19
9162 1.3752e-01 2.8351e-04 5.6260e-04 0:00:01 18
9163 8.6153e-02 1.9868e-04 4.6330e-04 0:00:01 17
9164 9.8575e-02 1.5263e-04 3.8020e-04 0:00:01 16
9165 9.0847e-02 1.3064e-04 3.1443e-04 0:00:00 15
9166 7.8705e-02 1.2244e-04 2.6601e-04 0:00:00 14
9167 6.7342e-02 1.1726e-04 2.2805e-04 0:00:00 13
9168 5.7641e-02 1.1173e-04 1.9637e-04 0:00:00 12
9169 4.9169e-02 1.0528e-04 1.6965e-04 0:00:00 11
9170 4.1773e-02 9.8476e-05 1.4724e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9171 3.5494e-02 9.1997e-05 1.2836e-04 0:00:00 9
9172 3.0409e-02 8.5904e-05 1.1226e-04 0:00:00 8
9173 2.6330e-02 8.0226e-05 9.8539e-05 0:00:00 7
9174 2.3042e-02 7.4963e-05 8.6743e-05 0:00:00 6
9175 2.0157e-02 7.0185e-05 7.6558e-05 0:00:00 5
9176 1.8146e-02 6.5682e-05 6.7773e-05 0:00:00 4
9177 1.5606e-02 6.1606e-05 6.0067e-05 0:00:00 3
9178 1.4080e-02 5.7731e-05 5.3370e-05 0:00:00 2
9179 1.2180e-02 5.4216e-05 4.7543e-05 0:00:00 1
9180 1.1026e-02 5.0895e-05 4.2531e-05 0:00:00 0
step flow-time flow-time cl-1
505 2.5250e+02 2.5250e+02 -3.1458e-01
Flow time = 252.5s, time step = 505
3 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9180 1.1026e-02 5.0895e-05 4.2531e-05 0:00:01 20
9181 4.3899e-01 4.7196e-04 6.8224e-04 0:00:01 19
9182 1.3897e-01 2.7842e-04 5.6348e-04 0:00:01 18
9183 8.5966e-02 1.9314e-04 4.6680e-04 0:00:01 17
9184 9.7223e-02 1.4731e-04 3.8415e-04 0:00:01 16
9185 8.9636e-02 1.2623e-04 3.1788e-04 0:00:00 15
9186 7.8436e-02 1.1862e-04 2.6909e-04 0:00:00 14
9187 6.7787e-02 1.1376e-04 2.3022e-04 0:00:00 13
9188 6.0244e-02 1.0821e-04 1.9757e-04 0:00:00 12
9189 5.1296e-02 1.0270e-04 1.6986e-04 0:00:00 11
9190 4.5332e-02 9.6513e-05 1.4662e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9191 3.8048e-02 9.0494e-05 1.2695e-04 0:00:00 9
9192 3.3448e-02 8.4324e-05 1.1044e-04 0:00:00 8
9193 2.7908e-02 7.8757e-05 9.6301e-05 0:00:00 7
9194 2.4558e-02 7.3505e-05 8.4377e-05 0:00:00 6
9195 2.0648e-02 6.8767e-05 7.4146e-05 0:00:00 5
9196 1.8202e-02 6.4264e-05 6.5426e-05 0:00:00 4
9197 1.5927e-02 6.0183e-05 5.7984e-05 0:00:00 3
9198 1.3523e-02 5.6449e-05 5.1561e-05 0:00:00 2
9199 1.2161e-02 5.2906e-05 4.6058e-05 0:00:00 1
9200 1.0480e-02 4.9660e-05 4.1268e-05 0:00:00 0
step flow-time flow-time cl-1
506 2.5300e+02 2.5300e+02 -2.2123e-01
Flow time = 253s, time step = 506
2 more time steps
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9200 1.0480e-02 4.9660e-05 4.1268e-05 0:00:01 20
9201 4.3884e-01 4.6403e-04 6.8509e-04 0:00:01 19
9202 1.3990e-01 2.6965e-04 5.6064e-04 0:00:01 18
9203 8.6040e-02 1.8665e-04 4.6218e-04 0:00:01 17
9204 9.8118e-02 1.4228e-04 3.7862e-04 0:00:01 16
9205 9.0803e-02 1.2228e-04 3.1353e-04 0:00:00 15
9206 7.9376e-02 1.1507e-04 2.6567e-04 0:00:00 14
9207 6.8013e-02 1.1105e-04 2.2780e-04 0:00:00 13
9208 5.7917e-02 1.0633e-04 1.9599e-04 0:00:00 12
9209 5.0870e-02 1.0053e-04 1.6946e-04 0:00:00 11
9210 4.2427e-02 9.4987e-05 1.4696e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9211 3.7388e-02 8.8988e-05 1.2788e-04 0:00:00 9
9212 3.1434e-02 8.3521e-05 1.1153e-04 0:00:00 8
9213 2.7943e-02 7.7945e-05 9.7579e-05 0:00:00 7
9214 2.3843e-02 7.3055e-05 8.5649e-05 0:00:00 6
9215 2.1518e-02 6.8254e-05 7.5579e-05 0:00:00 5
9216 1.9001e-02 6.3910e-05 6.7020e-05 0:00:00 4
9217 1.6176e-02 6.0019e-05 5.9658e-05 0:00:00 3
9218 1.4547e-02 5.6156e-05 5.3283e-05 0:00:00 2
9219 1.2468e-02 5.2775e-05 4.7744e-05 0:00:00 1
9220 1.1314e-02 4.9427e-05 4.2914e-05 0:00:00 0
step flow-time flow-time cl-1
507 2.5350e+02 2.5350e+02 -8.6494e-02
Flow time = 253.5s, time step = 507
1 more time step
Updating solution at time levels N and N-1.
done.
iter continuity x-velocity y-velocity time/iter
9220 1.1314e-02 4.9427e-05 4.2914e-05 0:00:01 20
9221 4.3832e-01 4.5783e-04 6.7495e-04 0:00:01 19
9222 1.3528e-01 2.6640e-04 5.6223e-04 0:00:01 18
9223 8.5758e-02 1.8487e-04 4.6796e-04 0:00:01 17
9224 9.6742e-02 1.4153e-04 3.8453e-04 0:00:01 16
9225 8.8894e-02 1.2134e-04 3.1856e-04 0:00:00 15
9226 7.7572e-02 1.1479e-04 2.6978e-04 0:00:00 14
9227 6.6914e-02 1.1057e-04 2.3102e-04 0:00:00 13
9228 5.7878e-02 1.0571e-04 1.9864e-04 0:00:00 12
9229 5.0316e-02 1.0005e-04 1.7150e-04 0:00:00 11
9230 4.4944e-02 9.4053e-05 1.4881e-04 0:00:00 10
iter continuity x-velocity y-velocity time/iter
9231 3.7785e-02 8.8516e-05 1.2955e-04 0:00:00 9
9232 3.3771e-02 8.2789e-05 1.1323e-04 0:00:00 8
9233 2.8555e-02 7.7577e-05 9.9289e-05 0:00:00 7
9234 2.5491e-02 7.2465e-05 8.7473e-05 0:00:00 6
9235 2.1694e-02 6.7920e-05 7.7386e-05 0:00:00 5
9236 1.9480e-02 6.3610e-05 6.8782e-05 0:00:00 4
9237 1.6655e-02 5.9786e-05 6.1303e-05 0:00:00 3
9238 1.5045e-02 5.6113e-05 5.4851e-05 0:00:00 2
9239 1.3052e-02 5.2739e-05 4.9196e-05 0:00:00 1
9240 1.1861e-02 4.9502e-05 4.4241e-05 0:00:00 0
step flow-time flow-time cl-1
508 2.5400e+02 2.5400e+02 5.8989e-02
Flow time = 254s, time step = 508
>
adjoint/ parallel/ server/
define/ parametric-study/ solve/
display/ plot/ surface/
exit preferences/ views/
file/ print-license-usage
mesh/ report/
> ; 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.
75.4%
Done.
Writing "| gzip -2cfv > \"cyl.dat.gz\""...
35.6%
Done.
> ; Exit FLUENT
exit
Auto-Transcript Stop Time: 11:17:37, 12 Nov 2024
Total Transcript Time: 0 Minute 41 Second.
Automatic transcript closed.
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.