A hands-on introduction to preCICE, recommended for new users that want to learn how to couple their own codes and beyond.

About the course

Since 2020, we have been developing a dedicated training course on preCICE. Originally conceptualized for beginners, more and more content for advanced users has been added. We regularly give the complete course at the preCICE workshops and parts of it at various different occasions (for example as a minitutorial at SIAM CSE 2023. We also offer to give private and bespoke versions of the course through the preCICE support program. Please note that the material of the course (besides community-contributed modules) is not distributed with a FOSS license, in contrast to almost everything else we do.

Teaching concept

The course is organized in separate modules, which can be combined in various different ways. Each module typically takes 120 to 150 minutes to complete. We start each module with a short presentation explaining some background and giving an overview of the tasks. Then, students work on the tasks in a hands-on fashion, individually or in groups. Questions are answered individually by typically several instructors. We close each module by discussing solution approaches and open problems all together. We recommend using the preCICE Demo Virtual Machine to follow the tasks. The actual course material is tailored to the needs of each event and distributed via download links.

Content

The course currently consists of four modules. Several more will follow.

Basics

We couple two simple Python codes, discussing the basic methods of the preCICE API.

Basics training: Configuration

Tools

We take a tour over available tools to configure, understand, and post-process preCICE simulations. More specifically, we have a look at the preCICE logger, config visualizer, mesh exports, and watchpoints of preCICE. We also discuss common tips for visualizing partitioned simulations in ParaView.

Basics training: Tools

Implicit coupling

We use a conjugate heat transfer scenario coupling OpenFOAM with Nutils to study implicit coupling, including acceleration methods.

Basics training: Implicit coupling

Data mapping

We explore aspects of accuracy and efficiency in data mapping, using ASTE.

Basics training: Mapping

Workflow for FSI simulations

In this community-contributed part of the course, we are going step by step through the process of creating a fluid-structure interaction simulation coupling CalculiX and OpenFOAM. We start by creating the meshes for both solvers, using FreeCAD and snappyHexMesh. We then setup and run single-physics simulations, before we couple them.

Application training: FSI workflow

How to prepare?

In our training courses, we typically bring along some Ubuntu Live USB sticks with all the dependencies pre-installed. They should work on any laptop with an x86 CPU, as long as you have the rights to boot from USB. In particular, these do not work on Apple silicon systems.

In case you would like something more permanent, but still with low setup effort, you can download the preCICE Demo Virtual Machine. Note that downloading this will take a while, so better prepare this early enough.

Finally, in case you prefer to install everything in your laptop, you will need the following:

  • preCICE
  • preCICE Python bindings:
    • Create a virtual environment: python3 -m venv .venv && source .venv/bin/activate. As long as the environment is active, you will see (venv) before your command prompt. You need to activate the venv in new terminal windows.
    • Install the bindings: pip3 install pyprecice (check with running import precice in a Python interpreter)
  • matplotlib: In the same virtual environment, run pip3 install matplotlib
  • ParaView (visualization, used in most modules apart from the basics)

The tools module also needs (all optional):

  • preCICE config visualizer (check with running precice-config-visualizer --help)
    • Optionally, install the precice-config-visualizer-gui as well.
  • gnuplot (check with gnuplot --help)

The implicit coupling module also needs:

  • OpenFOAM (openfoam.com): See the Quickstart page (check with running buoyantPimpleFoam -help)
  • OpenFOAM-preCICE (check with running the Quickstart tutorial)
  • Nutils (installed automatically when running)

The mapping module also needs:

  • ASTE (check by running ./precice-aste-run --help from the ASTE build directory)

The FSI workflow module also needs:

  • OpenFOAM (openfoam.com): See the Quickstart page (check with running pimpleFoam -help)
  • OpenFOAM-preCICE (check with running the Quickstart tutorial)
  • CalculiX and the CalculiX adapter (check by running ccx_preCICE)
  • FreeCAD 0.21 or later (check by starting the GUI)
  • ccx2paraview (pip3 install ccx2paraview, check by starting a Python terminal and executing import ccx2paraview)
  • PyFoam (pip3 install pyfoam, check by running pyFoamPlotWatcher.py --help)