[zongo]

Hi,


I'm using the DTCHullWave case to calculate the forces received by a hull depending on the wave properties (mainly wavelenght and amplitude.


Everything worked fine with the default stl file, I just had to use the "forces" function in the controlDict file, and the "forces" file generated would allow me to plot the forces received by the hull patch (20s simulated, forces are sinus waves as expected).



However, for my work I had to change the dimensions of the fied (easily done in blockMesh), and use a smaller field instead (20*0.8*1.41). The water height is 0.5, and I changed the values accordingly in the href and the waveProperties file.


I'm also using a 30% scaled version of the defaut stl so that it can fit in the new field. I have adapted the boxes dimensions in the toposet files (i'm using 5 of 6 because meshing is too long otherwise and I don't need very precise values).



I have also changed the mass in the dynamicMeshDict file (because since the 30% scaled stl has smaller volume, it would sink), and the CoR value in both this file and the controlDict file (where the CoR is requested for the "forces" function).


Even after doing all this, I can't seem to get the same results as with the default stl. The simulation is very slow and diverges aroud 1.5s, and the plotted forces makes no sense. Also I can see in the short video that the hull isn't moving at all, unlike the defaut stl (which translates with z and rotates with y, as mentionned in the dynamicMeshDict file).



Any help or idea would be welcome.


Thank you for your time and have a nice day.

[ibe]

Hello,

This post mentions using the forces function defined in the system/controlDict file.



I've been able to (re)run the DTChull example, but I don't see any specific output file involving the forces.

can you suggest or reference instructions on how to find these outputs ?
Thanks,






// https://www.openfoam.com/documentati...s.html#details

functions
{
forces
{
type forces;
libs ("libforces.so");
patches (hull);
log on;
writeControl timeStep;
writeInterval 1;
CofR (2.929541 0 0.2);
}
}