The OpenFOAM-preCICE adapter is a plug-in for the CFD software OpenFOAM which allows it to connect to the open-source coupling library preCICE. Initially, the adapter only supported coupling over a surface at the interface between two subdomains. Since there are various cases in practice where the subdomains can overlap, this project adds the feature of volume coupling, i. e. coupling over cells of the internal field of the domain.

We review contributions from the community which have implemented volume coupling for specific applications and unify them into a comprehensive long-term component of the adapter. We discuss how to best incorporate the new feature into the adapter and we integrate elements of previous work, resulting in a volume coupling extension with a configurable coupling region. Finally, we validate our implementation with a simulation scenario for each coupling direction (data transfer to and from OpenFOAM).