Hi @Makis,
Some news coming from this FSI experiment !
I have been working on the Solid code for quite a bit of time, it’s better, and now I am coming back once again to the FSI interactions. I’ve not reached what I want but I think I’m getting there.
To start off, let me do a quick recap of my framework:
- A vertex-centred FVM solid mechanics code based on OpenFoam-6,
- Any simple CFD solver from OpenFoam-6 (pimpleFoam will do),
- The openfoam-adapter, more especially the branch of @JSeuffert
- I want to reproduce the perpendicular flap problem.
I would like to achieve first a one-way coupling; namely and in simple words, I would like to solve a prescribed motion on the Solid side, and pass the displacements to my Fluid solver, so its velocity field is updated accordingly.
At the moment, I am able to make preCICE run both simulations in conjunction. Following is the content of the files of interest:
precice.config.xml
<?xml version="1.0"?>
<precice-configuration>
<log>
<sink filter="%Severity% > debug and %Rank% = 0" format="---[precice] %ColorizedSeverity% %Message%" enabled="true"/>
</log>
<solver-interface dimensions="3">
<data:vector name="Forces"/>
<data:vector name="Displacements"/>
<mesh name="Fluid-Mesh-Faces"> <use-data name="Forces"/> </mesh>
<mesh name="Fluid-Mesh-Nodes"> <use-data name="Displacements"/> </mesh>
<mesh name="Solid-Mesh-Nodes"> <use-data name="Forces"/> <use-data name="Displacements"/> </mesh>
<participant name="Fluid">
<use-mesh name="Fluid-Mesh-Faces" provide="yes"/>
<use-mesh name="Fluid-Mesh-Nodes" provide="yes"/>
<use-mesh name="Solid-Mesh-Nodes" from="Solid"/>
<write-data name="Forces" mesh="Fluid-Mesh-Faces"/>
<read-data name="Displacements" mesh="Fluid-Mesh-Nodes"/>
<mapping:rbf-thin-plate-splines direction="write" from="Fluid-Mesh-Faces" to="Solid-Mesh-Nodes" constraint="conservative"/>
<mapping:rbf-thin-plate-splines direction="read" from="Solid-Mesh-Nodes" to="Fluid-Mesh-Nodes" constraint="consistent"/>
</participant>
<participant name="Solid">
<use-mesh name="Solid-Mesh-Nodes" provide="yes"/>
<read-data name="Forces" mesh="Solid-Mesh-Nodes"/>
<write-data name="Displacements" mesh="Solid-Mesh-Nodes"/>
<!--watch-point mesh="Solid" name="point1" coordinate="0.6;0.2;0." /-->
</participant>
<m2n:sockets from="Fluid" to="Solid"/>
<coupling-scheme:serial-implicit>
<time-window-size value="0.01" />
<max-time value="0.25"/>
<participants first="Fluid" second="Solid"/>
<exchange data="Forces" mesh="Solid-Mesh-Nodes" from="Fluid" to="Solid"/>
<exchange data="Displacements" mesh="Solid-Mesh-Nodes" from="Solid" to="Fluid" initialize="0" />
<max-iterations value="50"/>
<relative-convergence-measure limit="1e-4" data="Displacements" mesh="Solid-Mesh-Nodes"/>
<relative-convergence-measure limit="1e-4" data="Forces" mesh="Solid-Mesh-Nodes"/>
<extrapolation-order value="2"/>
<acceleration:IQN-ILS>
<data name="Displacements" mesh="Solid-Mesh-Nodes"/>
<preconditioner type="residual-sum"/>
<filter type="QR1" limit="1e-6"/>
<initial-relaxation value="0.1"/>
<max-used-iterations value="50"/>
<time-windows-reused value="10"/>
</acceleration:IQN-ILS>
</coupling-scheme:serial-implicit>
</solver-interface>
</precice-configuration>
Fluid/system/preciceDict
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object preciceDict;
}
preciceConfig "precice-config.xml";
participant Fluid;
modules (FSI);
interfaces
{
Interface1
{
mesh Fluid-Mesh-Faces;
patches (interface);
locations faceCenters;
readData ( );
writeData ( Forces );
};
Interface2
{
mesh Fluid-Mesh-Nodes;
patches (interface);
locations faceNodes;
readData ( Displacements );
writeData ( );
};
};
FSI
{
rho rho [1 -3 0 0 0 0 0] 1100;
}
Solid/system/preciceDict
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object preciceDict;
}
preciceConfig "precice-config.xml";
participant Solid;
modules (FSI);
interfaces
{
Interface1
{
mesh Solid-Mesh-Nodes;
patches (interface);
locations faceNodes;
readData ( Forces );
writeData ( Displacements ); //Displacements //u
};
};
FSI
{
solverType incompressible;
namePointDisplacement u;
rho rho [1 -3 0 0 0 0 0] 1100;
}
Note: actually at the moment ./Allrun starts both solvers but they stay stuck at
—[preciceAdapter] [DEBUG] Initalizing the preCICE solver interface…
—[precice] Setting up master communication to coupling partner/s
The problem might come from a misreading of the data by the solver and/or preCICE, but I’m not comfortable at all with the setup of the coupling ( the 3 files above ).
I don’t want to clutter my post much more so do not hesitate to ask me for logs, setup files and whatsoever.
Keep documenting what you are doing and it would be nice to make a summary once you manage to make it working. I hope I can help in the way.
. A coarse summary of my progress is that I have been working on the penultimate commit of the PR, which I am now trying to compile.