Coupling Adapter Infrastructure (preCICE & CWIPI)
This directory implements the coupling infrastructure for OpenRadioss, enabling data exchange between OpenRadioss and external solvers via the preCICE and CWIPI libraries. The design supports both C++ and Fortran integration, with a separation between the C interface, C++ adapters, and Fortran bindings.
Architecture Overview
We are using preCICE v3 API, and CWIPI default (legacy) API for coupling. The architecture consists of:
- C Interface (coupling_c_interface.cpp/.h): Exposes a C API for use by Fortran and other languages. All coupling operations (create, configure, initialize, data exchange, advance, finalize) are routed through this interface.
- C++ Adapters:
- PreciceCouplingAdapter: Implements coupling using the preCICE library.
- CwipiCouplingAdapter: Implements coupling using the CWIPI library.
- DummyCouplingAdapter: Fallback for builds without preCICE or CWIPI.
- Factory (coupling_factory.cpp): Instantiates the correct adapter at runtime based on build flags.
- Fortran Interface (coupling_adapter.F90): Fortran module that calls the C interface for coupling operations.
Main Data Flow
- Creation: Fortran or C code calls coupling_adapter_create() to obtain a new adapter instance.
- Configuration: coupling_adapter_configure() loads a config file and sets up the adapter (participant names, mesh, data types, etc.).
- Mesh/Node Setup: coupling_adapter_set_nodes() and (for CWIPI) coupling_adapter_set_mesh() define the mesh and coupling nodes.
- Initialization: coupling_adapter_initialize() sets up the coupling, mesh vertices, and communication.
- Data Exchange: coupling_adapter_write_data() and coupling_adapter_read_data() transfer data (displacements, forces, positions) between OpenRadioss and the coupled solver.
- Advance: coupling_adapter_advance() advances the coupling by one time step.
- Finalization: coupling_adapter_finalize() cleans up resources.
Adding a New Adapter
- Implement a new subclass of CouplingAdapter in C++.
- Implement all required virtual methods (see coupling.h).
- Add the new adapter to coupling_factory.cpp.
- Update the C interface if new functionality is needed.
- Document the new adapter in this README.
Key Files
Function Mapping Table
| C Interface Function | preCICE Adapter Method | CWIPI Adapter Method | Underlying Library Calls |
| coupling_adapter_create | PreciceCouplingAdapter() | CwipiCouplingAdapter() | - |
| coupling_adapter_destroy | Destructor | Destructor | finalize(), cwipi_finalize() |
| coupling_adapter_configure | configure() | configure() | precice::Participant, cwipi_init |
| coupling_adapter_set_nodes | setNodes() | setNodes() | - |
| coupling_adapter_set_mesh | - | setMesh() | - |
| coupling_adapter_initialize | initialize() | initialize() | precice::Participant, cwipi_create_coupling, cwipi_define_mesh, cwipi_locate |
| coupling_adapter_write_data | writeData() | writeData() | precice::writeData, cwipi_issend |
| coupling_adapter_read_data | readData() | readData() | precice::readData, cwipi_irecv |
| coupling_adapter_advance | advance() | advance() | precice::advance, cwipi_locate |
| coupling_adapter_finalize | finalize() | finalize() | precice::finalize, cwipi_finalize |
Build Flags
- run ./build_script.sh -arch=linux64_gf -mpi=ompi -cwipi=/absolute/path/to/cwipi. It will define WITH_CWIPI that enables adapter.
- run ./build_script.sh -arch=linux64_gf -mpi=ompi -preCICE. It will define WITH_PRECICE that enables preCICE adapter.
References
1.15.0