Prescribing the motion of individual particles on the boundary

I was wondering if it is possible to prescribe the x,y,z position over-time for individual particles on the boundary. I understand that there is the 'predefined movement with data from an external file' but this motion is applied to an entire object.

I am trying to apply peristaltic contractions to a cylindrical geometry.

Comments

  • It could be

    External motions are applied to a set of particles under mkbound... so that you can do that

    Regards

  • I thought this motion is applied to the entire set of particles as a whole, but I am wanting to prescribe the motion of individual particles.

  • Therefore create one particle under one mk

    Regards

  • I was looking at the "Casedef Geometry Commands" section of the documentation, but I can't see to figure out how to specify the mk value of an individual particle. The drawing options are only lines, triangles, boxes, pyramid, prism etc. There isn't an option to specify just a single point.

  • DualSPHysics_v5.0\doc\xml_format\CaseTemplate.xml:  

            <drawpoint x="0" y="0" z="0" />

  • Thanks for this! I tried this approach, it worked, but I found that I had to re-compile DualSPHysics with '#define CODE_SIZE4' to use more than 2000 mk values (which I need to capture the resolution of boundary particles). This lead to a huge loss in performance, as expected.

    Is there no way to use the same mk value for all the boundary particles, but to somehow use an individual particle's ID to prescribe it's motion. Or does DualSPHysics not carry this information i.e. it just treats all the particles with a certain mk value as a group?

    Another question I had was, is it possible to use different inter-particle distances i.e. use a larger value for the boundary but a smaller one for the fluid domain?

  • edited February 2023

    Q: Is there no way to use the same mk value for all the boundary particles, but to somehow use an individual particle's ID to prescribe it's motion. Or does DualSPHysics not carry this information i.e. it just treats all the particles with a certain mk value as a group?

    R: NO... sorry, perhaps we can think on a solution ad hoc for you...


    Q: Another question I had was, is it possible to use different inter-particle distances i.e. use a larger value for the boundary but a smaller one for the fluid domain?

    R: Variable particle resolution is under development right now.

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