floating body movement and the case exclude particles
The floating body should move under the impact of water, why sometimes the floating body is not fixed when setting the model, and the floating body does not move in the simulation.
And what are the conditions for excluding particles? What I know is that if the density or position exceeds a certain range, particles will be excluded, but there seem to be other situations in addition to this. It is only a prompt in the command window, but it does not say why the particles are excluded.
I am very confused about the above two problems, but these two problems often appear in my simulation.
Does anyone know if any relevant information can help me? thank you very much
Comments
PartVTKOut will create files with all that information.
So that using (in .bat): %partvtkout% -dirin %diroutdata% -savevtk %dirout2%/PartFluidOut -SaveResume %dirout2%/_ResumeFluidOut
The file "_ResumeFluidOut.csv" is created, where you can see how many particles were excluded for position (Nout_pos), for density (Nout_Rhop), for wrong velocity (Nout_Vel).
Regards
@Alex Thanks for your reply very much! Yes, I can indeed generate this file, but I don't know how to use this file, so can it be understood that there are three possibilities for excluded particles, namely position error, density error and velocity error. For these problems, in general, according to experience, how to correct it? What parameters should I pay attention to adjusting?
I have checked the "_ResumeFluidOut.csv" file and I found all particles that excluded are for the reason of position. what can I do? I visualized these particles and found that the position in the y direction is wrong. My simulation is a 2D model, but the displacement in the y direction is generated during the simulation.
In the parameters section, go down to "simulationdomain" and use "+100%" at the direction you want to extend.
For minimum values remember to use "-" instead of "+".
Remember that the initial grid is based on the particle distribution, if you move it a lot you need to extend the simulation domain as explained to you here.
Kind regards
"My simulation is a 2D model, but the displacement in the y direction is generated during the simulation"
That is not possible at all ...
Check XML_GUIDE.pdf
When pointmin.y=pointmax.y then the simualtion is 2D
@Alex indeed, that's how I do it. I have read the instruction book carefully. My operation is as follows: pointmin.y=pointmax.y
But I checked all the excluded particles, all because of the wrong position, and their y-coordinates are all not 0, but a floating number close to 0 (I think this is caused by numerical error), but I am very Confused how to solve the problem of these particles being excluded?
If you still think it's impossible, I can put the relevant evidence here😁
Thanks a lot for your suggestion, I'll try it. And I am more confused about the grid you mentioned above: Remember that the initial grid is based on the particle distribution, It seems that there is no document mentioning this, how is this grid determined? Is there any more detailed information about this?
It is something common in all SPH methods that it is necessary to generate a neighbour list for efficient calculation of momentum equation etc. In DualSPHysics this is done by "gridding" the particle distribution in the background to different cells and then loop over these cells for computations.
Googling neighbourlist algorithms SPH should be a start. To see your background grid, check some of the Cfg_XXXX.vtk files, one of them should be it.
Kind regards
@Asalih3d Oh，I have understand what you mean. It's for computation efficiency. The file CfgInit_MapCells.vtk is what you say.
Thanks a lot!
Best regards
As mentioned before, there are no displacements in Y-direction for sure.
Particles are being excluded due to move out of limits in X and Z, but never in Y-direction. I am 100% sure ;)
Send to us your XML file, please.
@Alex Ok, I have sent it to you through another conversation, can you please help me to see where I am doing wrong?
@Alex I have sent my xml file. can you please help me to see where I am doing wrong?