A Precice-Fmi Runner to Couple FMUs to PDE-Based Simulations

Partitioned simulation or co-simulation allows simulating complex systems by breaking them up into smaller subsystems. The Functional Mock-Up Interface (FMI) enables co-simulation for models based on ODEs and DAEs, but typically not PDEs. However, only PDE-based models are able to accurately simulate physical aspects requiring spatial resolution, such as heat transfer or fluid-structure interaction. We present a preCICE-FMI runner software to integrate FMUs with the open-source coupling library preCICE. preCICE couples PDE-based simulation programs, such as OpenFOAM or FEniCS, in a black-box fashion to achieve partitioned multi-physics simulations. The runner serves as an importer to execute any FMU and to steer the simulation. Additionally, it calls preCICE to communicate and coordinate with other programs. The software is written in Python and relies on the Python package FMPy. We showcase two example cases for the coupling of FMUs to ODE- and PDE-based models.