how to specify boundary conditions after slicing the fluid domain

I am simulating a foil in Ansys Fluent. When I used inflation for meshing, orthogonal quality hits under 0.1 in trailing edge, which is not desirable. Therefore, I used slice in trailing edge in order to fix this flaw.

However, the fluid domain is divided into two distinct fluid domains. I do not know how to define boundary conditions (inlet, outlet, walls, ...) after slicing which leads to two separate domains. Can you help me how to specify boundary conditions in this case?


  • Set the slice faces as Interior.

    Use Shared Topology and delete any automatically generated contacts to minimize the interfaces that are created after slicing.

  • shayanmehrshayanmehr Member
    edited September 28

    Dear friend thank you for your response.

    But what are inlet, outlet and walls for this case?

    I am confused how to set them because there are two separate domains (with the same fluid characteristics). Two domains can be seen in below picture, the left one which is in green color and the right one.

  • The inlet is the left face of the left domain, the outlet is the right face of the right solid.

    I expect you should choose Walls for the top and bottom faces of the two domains.

    Use Symmetry on the front and back faces of the two domains.

    Use Interior for the faces that touch in the center.

  • When I used Shared Topology, the orthogonal quality around sharp trailing edge decreased again. Is it ok if I don't use Shared Topology?

    Also I have 2 cell zones after slicing, should I merge these 2 cell zones or no?

  • RobRob UKForum Coordinator

    If you don't you'll get a mesh interface just as the flow gets interesting. If the cell size is near enough the same you should be OK, but it's not something I'd recommend. Please post some images of the mesh so we can see what's going on.

    Multiple fluid domains are fine; I usually have a few, and they're regularly used for things like source terms and moving reference frames.

  • shayanmehrshayanmehr Member
    edited September 29

    It is my first mesh and as you can see, the mesh on the right side is not the same as the left side.

    so I used patch conforming method in order to make the mesh of the right side similar to the left side with tetrahedrons method:

    but after that, bad mesh quality appears in the trailing edge as shown in below picture:

    do you have any suggestion to solve this issue?

  • RobRob UKForum Coordinator

    Try a finer mesh towards the trailing edge. There's something very odd with the geometry in that area: what does the CAD look like?

  • Can you open the CAD file if I upload it?

  • Hello,

    As Ansys employees, we will not be able to download files attached on this Learning Forum.

    Please feel free to embed your screenshots directly in your post to highlight the features. As mentioned by Rob, I'd definitely try a finer mesh near the trailing edge.



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