Star-CCM+ — Single Case¶

A single case run is the simplest Star-CCM+ workflow — one simulation file, one set of conditions, run to completion. Use this when you are running a single configuration or testing a setup before scaling up.

For running multiple cases or parameter sweeps, see Design Manager.

Prerequisites¶

Before submitting, make sure you have: - A Star-CCM+ simulation file (.sim) - Any Java macros (.java) you want to run - An INI file (.ini) if you are overriding simulation parameters at runtime - A valid license key or license server address - Your input files organized in your home directory

Key Concepts¶

Java Macros¶

Java macros automate actions inside Star-CCM+ such as meshing, initialization, running, and exporting results. They are passed to the solver using the -batch flag and can be chained together in order:

-batch changeGeometry.java,mesh,SteadyState.java,run,exportResults.java

Built-in macros like mesh and run do not need a file — just include them by name in the chain.

INI Files¶

INI files let you override simulation parameters (e.g., angle of attack, freestream velocity) at runtime without editing the .sim file directly. This is useful when running the same simulation with different conditions.

Example:

-param AoA 5.0deg
-param freestream 50.0m/s

The corresponding parameters (AoA, freestream) must already be defined inside the .sim file for this to work.

User Inputs¶

At the top of the script, there is a clearly marked USER INPUTS section. This is the only part you should need to edit for most runs:

Variable	Description
`SIM_FILE`	Name of your `.sim` file
`CASELOG`	Name of the output log file
`MACROS`	Comma-separated list of macros to run in order
`INI`	INI file flag and filename (leave blank if not used)
`PODKEY`	Your Star-CCM+ pod key (if using pod licensing)
`LICS`	License server address (if using a license server)
`LICOPT`	Comment/uncomment to switch between pod key and license server

What the Script Does¶

1. Setup The script creates a machine file listing the allocated compute nodes, then creates a job-specific folder in scratch space using the job ID, job name, and date. Your input files are copied from your home directory to this scratch folder using rsync, and the script moves into that directory before doing anything else.

2. Execution Star-CCM+ is launched with the number of cores allocated by the scheduler ($PBS_NP), the specified macros, INI file, and license options. Output is redirected to your log file. Elapsed time is calculated and written to a stat.out file along with cell count and core count for reference.

3. Post-processing (optional) After the solver finishes, you can add additional commands to run post-processing scripts, generate plots, or convert image sequences to video. This section is clearly marked in the script.

4. Cleanup Results are copied back from scratch to your home directory using rsync. The scratch folder is then deleted to free up space.

Script¶

Download or reference the full script here: scripts/single_case.sh

Next: Design Manager