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# meshing
  • y

    Yann

    11/20/2025, 11:12 AM
    Also depends on your goal. If you want to do some RANS sims to get the polar curves of your aircraft, snappy should do the job but you'll have to accept its limitations (layers collapsing, not getting full layer coverage, etc)
  • l

    lennygo

    11/20/2025, 11:13 AM
    The goal is pretty clear
  • l

    lennygo

    11/20/2025, 11:13 AM
    Generate Aerodynamic plots of Lift, Drag and Moment Coefficient and judge the performance and stability of what is being designed
  • l

    lennygo

    11/20/2025, 11:15 AM
    Problem is the following: - low angles of attack / no seperation / wall functions above y+ 30 and easier calculation - higher angles of attack / seperation / y+ of 1 for correct prediction The first one is more relaxed and yet this already had the issues in the screenshot here If that is already wrong how can I approach the seperation region when Im sure that my seperation will not be predicted correctly
  • y

    Yann

    11/20/2025, 11:15 AM
    and what is being designed is a full aircraft?
  • l

    lennygo

    11/20/2025, 11:16 AM
    Its an aircraft yes
  • y

    Yann

    11/20/2025, 11:17 AM
    what's your reference case to assess if you get correct results?
  • l

    lennygo

    11/20/2025, 11:19 AM
    To make sure if I am in the right ballpark or not I had done a 2d study on the NACA0012 airfoil to see how fine the mesh had to be and that went well
  • l

    lennygo

    11/20/2025, 11:25 AM
    The results are also double checked with more simplified methods of lift and drag calculation that make sure its in the right ballpark
  • d

    DivU

    11/20/2025, 11:29 AM
    are there any resources on how I can mesh a 3D airfloil or balde in salome with quads?
  • z

    Zino

    11/20/2025, 12:06 PM
    Some nice hints here https://cfdmonkey.com/tips-and-tricks-for-significantly-improving-your-snappyhexmesh/
  • z

    Zino

    11/20/2025, 12:06 PM
    I've found many of the same things through experience
  • l

    lennygo

    11/20/2025, 12:21 PM
    Have done most of these things, so I guess for me its just keep hammering until I get something useful
  • z

    Zino

    11/20/2025, 12:33 PM
    Best of luck
  • l

    lennygo

    11/20/2025, 12:33 PM
    🫠
  • z

    Zino

    11/20/2025, 12:34 PM
    Have you tried something like gmsh or Salome?
  • z

    Zino

    11/20/2025, 12:34 PM
    (I haven't used them personally)
  • z

    Zino

    11/20/2025, 12:34 PM
    Snappy is fine for the sorts of geometries I deal with
  • l

    lennygo

    11/20/2025, 12:40 PM
    gmsh was not recommended, salome is too slow, however I do use Salome to import my step from fusion and convert it into a surface mesh which I use as a base STL for SHM
  • l

    lennygo

    11/20/2025, 12:40 PM
    just because salome gives a nice evenly distributed tri surface mesh
  • l

    lennygo

    11/20/2025, 12:40 PM
    my las ditch is Snappy to Polycells from a tri mesh, although i am unsure if that lets me put a boundary layer
  • h

    Hila

    11/20/2025, 12:41 PM
    Have you tried making a tri mesh with a boundary layer and then doing polyDualMesh?
  • l

    lennygo

    11/20/2025, 12:42 PM
    this is what I was gonna try to do now
  • h

    Hila

    11/20/2025, 12:48 PM
    Perfect. I made some simulations with a polyMesh and the convergence was insane good
  • l

    lennygo

    11/20/2025, 12:50 PM
    Yeah but I heard its painfully slow which is why I had dodged it for some time
  • h

    Hila

    11/20/2025, 12:52 PM
    it wasn't too bad in my case. The final mesh had 2 million cells
  • l

    lennygo

    11/20/2025, 1:05 PM
    Im probably gonna sit around 10 million
  • l

    lennygo

    11/20/2025, 1:05 PM
    how many cores how long?
  • l

    lennygo

    11/20/2025, 1:05 PM
    the meshing that is
  • l

    lennygo

    11/20/2025, 2:11 PM
    Did you use SHM and then converted to tri?