Fluid-Structure-Interaction (FSI) API

[michaelasprague]

This Discussion is for API planning around the fluid-structure-interaction (FSI) interface. The primary coupling target is Nalu-Wind (computational fluid dynamics) for geometry-resolved simulations. The secondary coupling target is AMR-Wind for actuator-line based simulations.

[michaelasprague]

Current interface code for coupling OpenFAST and Nalu-Wind:

https://github.com/gantech/OpenFAST/blob/f/br_fsi_2/glue-codes/openfast-cpp/src/OpenFAST.H
https://github.com/Exawind/nalu-wind/blob/master/src/aero/fsi/OpenfastFSI.C

Some notes from Ganesh:

• Look for all the function calls FAST.something in OpenfastFSI.C. This is for the blade-resolved FSI interface. The actuator side’s a little different.
• You want to follow the calls in Nalu-wind and not AMR-Wind as Nalu-wind calls the C++ API, while AMR-Wind directly calls the Fortran API. Also this allows for multiple outer iterations for tighter coupling.