pysyc error when adding MAPDL participant as session on Linux 25R2

[pshutche]

🔍 Before submitting the issue

• I have searched among the existing issues
• I am using a Python virtual environment

🐞 Description of the bug

I can connect MAPDL participant as session on windows 25R2 but not linux. I get:

pysyTraceback (most recent call last):
File "/lus01/pshutche/Antenna/Cylinder-vortex-shedding/pysyc-slurm/main.py", line 30, in
solid = syc.setup.add_participant(participant_session = mechanical)
File "/lus01/pshutche/AirbusHeli/pyenv/lib/python3.10/site-packages/ansys/systemcoupling/core/adaptor/impl/types.py", line 757, in call
return self.sycproxy.execute_injected_cmd(
File "/lus01/pshutche/AirbusHeli/pyenv/lib/python3.10/site-packages/ansys/systemcoupling/core/adaptor/impl/syc_proxy.py", line 128, in execute_injected_cmd
return cmd(**kwargs)
File "/lus01/pshutche/AirbusHeli/pyenv/lib/python3.10/site-packages/ansys/systemcoupling/core/adaptor/impl/injected_commands.py", line 93, in
"add_participant": lambda **kwargs: _wrap_add_participant(
File "/lus01/pshutche/AirbusHeli/pyenv/lib/python3.10/site-packages/ansys/systemcoupling/core/adaptor/impl/injected_commands.py", line 136, in _wrap_add_participant
return part_mgr.add_participant(
File "/lus01/pshutche/AirbusHeli/pyenv/lib/python3.10/site-packages/ansys/systemcoupling/core/participant/manager.py", line 84, in add_participant
part_state.participant_analysis_type = participant_session.get_analysis_type()
File "/lus01/pshutche/AirbusHeli/pyenv/lib/python3.10/site-packages/ansys/systemcoupling/core/participant/mapdl.py", line 72, in get_analysis_type
raise MapdlRuntimeError(f"Unsupported analysis type: {analysis_type}")
NameError: name 'MapdlRuntimeError' is not defined. Did you mean: 'RuntimeError'?

📝 Steps to reproduce

Submission script:

#!/bin/bash -l

Set slurm options as needed

#SBATCH --mail-user="paul.hutcheson@ansys.com"
#SBATCH --mail-type=ALL
#SBATCH --job-name Cylinder
#SBATCH --nodes=1
#SBATCH --partition=ottc02

--exclusive

#SBATCH --ntasks-per-node=32
#SBATCH --output=%x-%j.out
#SBATCH --error=%x-%j.err
#SBATCH --export=ALL

There is more flexibility with slurm:

--nodes=1

--ntasks-per-node=32

--ntasks=32

An example script to submit a co-simulation into a queue system

Set DISPLAY variable

export DISPLAY=ottvnc5:3

Optionally set paths to ANSYS and system coupling areas

export AWP_ROOT252=/ott/apps/software/v252

#export SYSC_ROOT=${AWP_ROOT251}/SystemCoupling
export SYSC_ROOT=${AWP_ROOT252}/SystemCoupling

print job start time and Slurm job resources

date
echo "SLURM_JOB_ID : "$SLURM_JOB_ID
echo "SLURM_JOB_NODELIST : "$SLURM_JOB_NODELIST
echo "SLURM_JOB_NUM_NODES : "$SLURM_JOB_NUM_NODES
echo "SLURM_NODELIST : "$SLURM_NODELIST
echo "SLURM_NTASKS : "$SLURM_NTASKS
echo "SLURM_TASKS_PER_NODE : "$SLURM_TASKS_PER_NODE
echo "working directory : "$SLURM_SUBMIT_DIR

#echo "Running System Coupling"
echo " System coupling main execution host is $HOSTNAME"
echo " Current working directory is $PWD"
echo " ANSYS install root is $AWP_ROOT252"
echo " System coupling root is $SYSC_ROOT"
echo " Run script is $1"
echo

Activate python environment

source ~/pyenv/bin/activate

Call python script

python main.py

pysyc script "main.py":

import ansys.fluent.core as pyfluent
import ansys.mapdl.core as pymapdl
import ansys.systemcoupling.core as pysystemcoupling

Fluent_folder = "Fluent_1"
Fluent_case = "Fluent-overset-laminar.cas.h5"
Fluent_cores = 32
#Fluent_ui_mode = "no_gui_or_graphics" # -g
Fluent_ui_mode = "no_gui" # -gu
Mechanical_folder = "Mechanical_2"
Mechanical_input = "Mechanical.dat"
Mechanical_cores = 16
#Mechanical_install = "/ott/apps/daily_builds/linx64/v252_Certified_Daily/ansys_inc/v252/ansys/bin/ansys252"

Start Mechanical

mechanical = pymapdl.launch_mapdl(nproc = Mechanical_cores,override = True, run_location = Mechanical_folder)

Read input file

mechanical.input(Mechanical_input)

Read scheduler options for Fluent

Start Fluent as session

fluent = pyfluent.launch_fluent(case_file_name = Fluent_case, processor_count = Fluent_cores, ui_mode = Fluent_ui_mode, cwd = Fluent_folder, graphics_driver = "null")

Start System Coupling

syc = pysystemcoupling.launch(start_output=True)

Connect participants

solid = syc.setup.add_participant(participant_session = mechanical)
fluid = syc.setup.add_participant(participant_session = fluent)

Create interface

fsi_interface = syc.setup.add_interface(
side_one_participant=solid,side_one_regions=['FSIN_1'],
side_two_participant=fluid,side_two_regions=['fsi'])

Create data transfers

force_transfer_name = syc.setup.add_data_transfer(
interface=fsi_interface,
target_side="One",
target_variable="FORC",
source_variable="force",
)

displacement_transfer_name = syc.setup.add_data_transfer(
interface=fsi_interface,
target_side="Two",
source_variable="INCD",
target_variable="displacement",
)

Set timestep

syc.setup.solution_control.time_step_size = 1e-3
syc.setup.solution_control.end_time = 1e-3
syc.setup.solution_control.maximum_iterations = 1
syc.solution.solve()

End parametric sweep

syc.solution.shutdown()
#fluent.exit()
#mechanical.exit()
syc.exit()

💻 Which operating system are you using?

Linux

📀 Which ANSYS version are you using?

25R2

🐍 Which Python version are you using?

3.10

📦 Installed packages

aiohappyeyeballs==2.6.1
aiohttp==3.11.18
aiosignal==1.3.2
ansys-api-fluent==0.3.35
ansys-api-mapdl==0.5.2
ansys-api-platform-instancemanagement==1.1.2
ansys-api-systemcoupling==0.2.0
ansys-api-tools-filetransfer==0.1.1
ansys-fluent-core==0.30.2
ansys-mapdl-core==0.70.2
ansys-mapdl-reader==0.54.2
ansys-math-core==0.2.2
ansys-platform-instancemanagement==1.1.2
ansys-systemcoupling-core==0.10.1
ansys-tools-filetransfer==0.1.1
ansys-tools-path==0.7.1
ansys-tools-visualization-interface==0.9.1
ansys-units==0.4.0
appdirs==1.4.4
async-timeout==5.0.1
attrs==24.2.0
certifi==2025.1.31
charset-normalizer==3.4.1
click==8.1.8
colorama==0.4.6
contourpy==1.3.1
cpylog==1.5.0
cycler==0.12.1
defusedxml==0.7.1
docker==7.1.0
docopt-ng==0.9.0
fonttools==4.56.0
frozenlist==1.6.0
geomdl==5.3.1
googleapis-common-protos==1.69.2
grpcio==1.71.0
grpcio-health-checking==1.62.3
grpcio-status==1.62.3
idna==3.10
importlib_metadata==8.6.1
joblib==1.4.2
kiwisolver==1.4.8
matplotlib==3.10.1
more-itertools==10.7.0
msgpack==1.1.0
multidict==6.4.3
nltk==3.9.1
numpy==1.26.4
packaging==24.2
pandas==2.2.3
pexpect==4.9.0
pillow==11.1.0
platformdirs==4.3.7
pooch==1.8.2
propcache==0.3.1
protobuf==4.25.6
psutil==7.0.0
ptyprocess==0.7.0
pyansys-tools-report==0.8.2
pyansys-tools-versioning==0.6.0
pyiges==0.3.1
pyNastran==1.4.1
pyparsing==3.2.1
python-dateutil==2.9.0.post0
pytz==2025.1
pyvista==0.45.0
PyYAML==6.0.2
regex==2024.11.6
requests==2.32.3
scipy==1.15.2
scooby==0.10.0
six==1.17.0
tabulate==0.9.0
tqdm==4.67.1
trame==3.9.0
trame-client==3.8.1
trame-common==0.2.0
trame-server==3.4.0
trame-vtk==2.8.15
trame-vuetify==3.0.1
typing_extensions==4.13.2
tzdata==2025.1
urllib3==2.3.0
vtk==9.4.2
websockets==15.0.1
wslink==2.3.3
yarl==1.20.0
zipp==3.21.0

[iboyd-ansys]

The main issue is that for some reason the analysis type cannot be identified. This reveals a secondary issue in that a non-existent exception type is thrown in the event that analysis type extraction fails. The secondary issue can be addressed by defining the specialised exception type or switching to a plain RuntimeError.

[sunilk-ai]

I’m not sure if this is the right place for this question, but I’d appreciate any insights. I reproduced the turek_hron_fsi2.py example from the PyAnsys System Coupling documentation.
The tip displacement matches the published results closely, but the lift and drag forces differ by about O(10²).
I’m using Ansys 2024 R1 with PyAnsys System Coupling and Fluent
Could this indicate a change in solver coupling behavior, or a possible inconsistency in the example setup?

[pshutche]

Hi @sunilk-ai probably not but I'll see how I can help redirect.

The Turek .py example results as it states are for illustrative purposes only. The examples are to show you how to use pysystemcoupling, they are not fsi validations.

If you want to use Turek for your own validation and want to query the results, I recommend logging a support ticket to investigate. If you do this, please provide full details of what you have done to obtain accurate results e.g. mesh and timestep refinement.

[sunilk-ai]

Thank you @pshutche for your response. Could you please guide me on how to generate a support ticket for further investigation? A link or the appropriate platform to raise the ticket would be very helpful.

[pshutche]

Presuming you are an Ansys/Synopsys customer with a paid TECS license and login to the support platform, you can use this link:

https://innovationspace.ansys.com/ansys-support-space/