Fluids

Fluids

how to specify boundary conditions after slicing the fluid domain

    • shayanmehr
      Subscriber

      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?

    • peteroznewman
      Subscriber
      Set the slice faces as Interior.nUse Shared Topology and delete any automatically generated contacts to minimize the interfaces that are created after slicing.n
    • shayanmehr
      Subscriber
      Dear friend thank you for your response.nBut what are inlet, outlet and walls for this case?nI 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.nn
    • peteroznewman
      Subscriber
      The inlet is the left face of the left domain, the outlet is the right face of the right solid.nI expect you should choose Walls for the top and bottom faces of the two domains.nUse Symmetry on the front and back faces of the two domains.nUse Interior for the faces that touch in the center.n
    • shayanmehr
      Subscriber
      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?nn
    • Rob
      Ansys Employee
      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. nMultiple fluid domains are fine; I usually have a few, and they're regularly used for things like source terms and moving reference frames. n
    • shayanmehr
      Subscriber
      It is my first mesh and as you can see, the mesh on the right side is not the same as the left side.nnso I used patch conforming method in order to make the mesh of the right side similar to the left side with tetrahedrons method:nnbut after that, bad mesh quality appears in the trailing edge as shown in below picture:ndo you have any suggestion to solve this issue?n
    • Rob
      Ansys Employee
      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?n
    • shayanmehr
      Subscriber
      Can you open the CAD file if I upload it?n
    • Karthik R
      Administrator
      Hello,nAs Ansys employees, we will not be able to download files attached on this Learning Forum. nPlease 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. nThanks.nKarthikn
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