I’m running the preCICE OpenFOAM Adapter in the FSI configuration.
When coupling a FSI case, I receive different aerodynamic forces from OpenFOAM (when coupling through preCICE) than they are evaluated/logged from OpenFOAM.
what I’ve done so far:
Export the forces of OpenFOAM in the post processing → one resulting force on the body
adding the forces received through preCICE together to receive a resulting force → they differ in factor 10 …
I’m assuming that I can just add all forces in one plane together (or do I need to transform them?)
I’m receiving the forces from OpenFOAM (fluid solver) via preCICE in my python script (solid solver).
No I’m using parallel explicit coupling without acceleration.
Ok. In general, the result should be the same. Some things to consider: the density is specified in different places (controlDict vs preciceDict). Is it the same? Do you have the same patches defined in order to evaluate the forces (should be only the coupling interface)? Which value do you expect? In order to exclude errors from the geometry, maybe use a unit length in z direction (assuming a 2D simulation).
Is there some documentation how the OpenFOAM Adapter calculates the force or do I have to read the code?
To exclude the possibility, that I have a mapping issue: Is it possible to log the coupling data from the OpenFOAM Adapter before sending it to preCICE?
Not really. I think the source code is rather intuitive in this regard and I think we already answered a similar question here in the forum. In general, the force computation is really similar to the force computation in OpenFOAM itself. Maybe you can find something about it and post a link below.
If you compile preCICE with python bindings can you not access the data using a python action? Your python action wouldn’t actually have to modify the data that is being read from the OpenFOAM adapter. You could simply use print commands to have values appear in the log.fluid or log.solid file.