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"WARNING: no discreteNormal is found " in the free energy model

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  • #4547
    zshi6193
    Participant

    Dear OpenLB,

    When I use the free energy model to simulate the multiphase flow, I get the following error:
    “WARNING: no discreteNormal is found”.
    I find this error is from the below codes:
    sOnBC1.addFreeEnergyWallBoundary( superGeometry, 2, alpha, kappa1, kappa2, h1, h2, 1 );
    sOnBC2.addFreeEnergyWallBoundary( superGeometry, 2, alpha, kappa1, kappa2, h1, h2, 2 );

    My simulation domain includes many sphere particles and some of particles are not completely inside the the boundary. That is, only part of sphere is inside the boundary. I think this is the reason for that error. Could someone can help me to solve it?
    Many thanks
    Best regards,
    Simon.

    #4548
    savis
    Participant

    Dear Simon,

    I believe that this is because of boundary nodes that aren’t beside any inner fluid nodes. You should hopefully be able to resolve this simply using “superGeometry.clean();” after the material numbers are assigned.

    Best wishes,
    Sam

    #4550
    zshi6193
    Participant

    Dear Sam,

    Thanks for your reply. I try to use “superGeometry.clean” and superGeometry.innerClean”. The same error comes out. But in fact, it seems this error doesn’t affect the results.

    Thanks
    Best regards,
    Simon.

    #4554
    mathias
    Keymaster

    Dear Simon,

    can you upload a schreenshot of your geometry?

    Best
    Mathias

    #4560
    zshi6193
    Participant

    • This reply was modified 2 years, 10 months ago by zshi6193.
    • This reply was modified 2 years, 10 months ago by zshi6193.
    • This reply was modified 2 years, 10 months ago by zshi6193.
    #4564
    zshi6193
    Participant

    • This reply was modified 2 years, 10 months ago by zshi6193.
    #4566
    zshi6193
    Participant

    Dear Mathias,

    Sorry I have difficulty in uploading the image.
    Here are the dropbox links of of my geometry. Thanks for your time. The highlight is the another boundary problem when two particles are close to each other. The multiphase model that I used is the free energy one.
    Thanks for your help.

    Best regards,
    Simon.
    https://www.dropbox.com/s/cjftfooi4i85qbn/1.PNG?dl=0
    https://www.dropbox.com/s/k6k4v8csgskjmrr/2.PNG?dl=0

    • This reply was modified 2 years, 10 months ago by zshi6193.
    #4569
    mathias
    Keymaster

    Dear Simon,

    can you check how many voxel are between the spheres? It should be at least two. By refining the mesh it should be ok.

    Best
    Mathias

    #4572
    zshi6193
    Participant

    Dear Dr Mathias,

    Thanks for your reply and suggestion. After I increase the mesh size, the problems are partly solved.

    Best regards,
    Simon

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