I Designed a concrete Capsule and tested in DualSPHysics. When inter particle distance set to  0.02, Simulation looks good. It floats vertically because most of the weight is at bottom that’s why gravity center is not in the middle. However resolution is too low, thus I decided to change it from 0.02 to 0.01. Simulation of DualSPHysics changed the gravity center and object float horizontal on the water surface. It is impossible because almost %30 weight is at bottom. Problem suppose to be conversion of solid model from low to better definition. Bottom side is not a hole however it removed bottom side thus volume of capsule got less and it's weight thus gravity center was changed perhaps.



  • Hello

    If you have imported a stl, you should be aware that by default it only fills the faces and it does not fully fill the body with particles.

    Kind regards

  • it was designed in Freecad with DesignSPHysics. I didn't import it. When inter particle distance set to 0.02, Simulation looks good. Problem started at high definition...

  • Hi,

    it is not clear in the video but I think your geometry is not filled (just capsule surface and separator inside). you can easily check it with paraview (use the clip function to see inside).

    Kind regards

  • @spide an object designed with DesignSPHysics will not be filled automatically as far as I know, only for spheres and cubes. I think you have to look through the XML documentation and learn about filling bodies. It should be possible in DesignSPHysics as well, you have to use "fillbox" or what it is called.

    Kind regards

  • @TPouzol inside of capsule is empty and there is a thickness on the walls. Bottom side is not empty. I used fillbox for wave tank before.

    I will try it for fill the body object. :)

  • @spide maybe for freecad, after being processed by gencase I think not !

    check what is actually created (see the .....Bound.vtk file).

    Using fillbox will give you the expected result

  • fill box fills with fluid which is water, how I can fill it with another density of fluid or bound while it is in water?

  • In design physics, I don't know... there may be a way to specify the mk and tell it if it's fluid or bound

    In xml files it's straight forward, you just wrutee your fillbox under the right mk.

    Good luck

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