FSI with OpenFOAM and in-house solver

[DavidSCN]

Hi @Stan,

@Stan

1. As stated in one thread, by employing ALE method, “the interface is fixed in the beginning of the simulation (location and number of nodes), but each node gets a displacement that is then used in the calculations”.
   Does that mean the values of displacement and pressure exchanged on the interface are obtained from the updated mesh cells? I’m kind of confused as in this video, the slides mention that preCICE maps in reference domain.
   Frédéric Simonis, Benjamin Uekermann, Hans-Joachim Bungartz · Adaptive Dynamic Meshes for Fully-Parallel Partitioned Multi-Physics in preCICE · SlidesLive

I guess you have already seen this thread from our FAQs. Let me try to explain it a little bit more in detail: In case you use an ALE approach, your solid domain and the respective part in the fluid moves during the simulation. However, the relative positions of the nodes at the interface are the same during the whole simulation so that the mapping problem is from a preCICE perspective the same as well. To answer your question: yes, preCICE maps the values in ‘reference configuration’, i.e. the initial mesh configuration, but that’s exactly what you want in case of an ALE approach. Of course, the exchanged values (at least in case of OpenFOAM) correspond from a solver perspective to the deformed configuration.

@Stan

2. As the OpenFOAM adapter has already been developed, I think the main work is to write an adapter for the in-house code. Is there any information for beginners about how to write an adapter? And when using the OpenFOAM adapter, are there any matters needing attention while adopting different slovers in OpenFOAM?

Yes, there is information. We have a dedicated section for this topic on our website. Similarly, we have collected all relevant information regarding OpenFOAM in the OpenFOAM adapter section on the website. IIRC there are also some threads about multi-phase flows with OpenFOAM in the forum.

Regards,
David