Star-CCM+ is a multiphysics software for simulating products under real-world conditions. Simcenter STAR-CCM+ brings a unique approach to design exploration and automated optimization to every engineer's CFD simulation tools.
Here is a quick, step-by-step guide to assist you through the various phases of executing a Star-CCM+ test case on Qarnot. Follow the guide!
To launch a Star-CCM+ simulation on Qarnot, you must authorize us to access your license. For more details, please contact our team at support-compute@qarnot-computing.com.
We will assume, from now on, that your license configuration with us is complete.
The StarCCM+ versions available on Qarnot are visible via the catalogue.
If you are interested in another version, please send us an email at support-compute@qarnot-computing.com.
To launch a task with a button click from our web interface, you can use this step-by-step tutorial.
If needed, here is a test case: cylindre_complet_extrusion_both_demi_DP_reconstruit_init.sim/.
To do this, the prerequisites are:
The following examples will show you in detail how to launch a task using a Python script.
This test case will show you how to launch a simulation with a complete cylinder model with geometry obtained by extrusion on the Star-CCM+ solver, using the test case cylindre_complet_extrusion_both_demi_DP_reconstruit_init.sim/.
Once the file is downloaded, place it in a directory named starccm_cylindre_test.
Once everything is configured, use the run-starccm.py script below to launch a minimalist computation on Qarnot, which uses 2 "Xeon" machines by default. If you want to explore more advanced options, the scripts below ("Batch Launch" and "SSH Launch") will likely interest you more.
To run thise scripts, simply copy the code into a Python script, place it at the same level as the starccm_cylindre_test folder, and execute python3 run-starccm.py & in your terminal. Your file structure should look like this:
├─ starccm_cylindre_test/
│ ├─ cylindre_complet_extrusion_both_demi_DP_reconstruit_init.sim
├─ run-starccm.py
Make sure you have copied your authentication token into the script (in place of <QARNOT_TOKEN>) to be able to launch the task on Qarnot. Retrieve it here.
For example, your input data will appear in the web interface as:
The script presented below allows you to explore the platform's more advanced features for a batch launch.
The script presented below allows you to connect to your container using the SSH protocol.
To run it, simply copy the previous code into a Python script, place it at the same level as the starccm_cylindre_test folder, and define your SSH key in the DOCKER_SSH parameters.
Also, make sure you have copied your authentication token into the script (in place of <QARNOT_TOKEN> ) to be able to launch the task on Qarnot.
Then execute the following command in your terminal:
python3 run-starccm-ssh.py
Please note that your Starccm command will vary depending on the number of instances. Considering TOTAL_PROCESSES = SETUP_CLUSTER_NB_SLOTS * NB_INSTANCES -
For a single node launch (NB_INSTANCES == 1), the command will be:
starccm+ -power -batch run -np {TOTAL_PROCESSES} cylindre_complet_extrusion_both_demi_DP_reconstruit_init_c4056f43d7.sim
And for a multi-node launch (NB_INSTANCES >= 2):
starccm+ -power -batch -mpi openmpi -mpiflags \"--mca btl ^openib,tcp --mca pml ucx --mca osc ucx –map-by l3cache –bind-to-core\" -machinefile /job/mpihosts -np run {TOTAL_PROCESSES} cylindre_complet_extrusion_both_demi_DP_reconstruit_init_c
For details on using Star-CCM+ on Qarnot, please consult our documentation. You will find useful advice on MPI clustering and available parameters.
You should now have a folder starccm_cylindre_test-out in your working directory on your computer and/or a starccm_cylindre_test-out bucket in Tasq containing all the output files.
You can directly view certain images and log files generated by the simulation, which are located in your output bucket, on Tasq. Your results will be stored in the starccm_cylindre_test-out bucket and can be retrieved in three ways:
For a large quantity of files or more than 5GB of data, it is advisable to use rclone (linux) or cyberduck (windows). These are two opensource S3 bucket management applications.
