Find answers, ask questions, and connect with our <br>community around the world.

Home Forums OpenFOAM Forum snappyHexMesh control

  • snappyHexMesh control

    Posted by Rituraj Borah on August 23, 2023 at 5:29 pm

    Dear OpenFOAM support,

    I have used snappyHexMesh to mesh the inside of a cylinder and obtained a mesh like this. My question the boundary layers actually formed on the two flat openings of the cylinder. But on the curved body of cylinder, I didn’t really get much layers. Actually if I want to simulate the flow through this cylinder, I want the opposite. No layers on the flat surfaces, but boundary layers on the curved walls. How to control snappyHexMesh according to my need?
    Thank you!

    Barış Bicer replied 9 months, 3 weeks ago 2 Members · 6 Replies
  • 6 Replies
  • Barış Bicer

    Moderator
    August 26, 2023 at 2:52 pm

    First you should separate the patch before the meshing and you should assign these patches where you wanna have boundary layer in the addinglayer stage of snappyHexMesh

    For your info

  • Rituraj Borah

    Member
    August 29, 2023 at 1:46 pm

    Thank you for your response!

  • Barış Bicer

    Moderator
    August 29, 2023 at 1:49 pm

    you are welcome

  • Rituraj Borah

    Member
    August 30, 2023 at 10:57 am

    Hi Barış, I tried to implement your solution to the problem. However in the snappyHexMeshDict, I cannot find a section where I can assign walls and patches. Do I have to make a separate boundary.dat file and then incorporate it in the snappyHexMeshDict?

  • Rituraj Borah

    Member
    August 30, 2023 at 11:39 am

    Just for the clarification of the problem:
    So, unlike the motorbike case, I am attempting to simulate the flow inside a channel network with many branches. So in the motorbike case, the blockMesh basically defines the computational domain and also the walls and patches can be defined in the blockMeshDict itself. However, in my case, the computational domain is the channel. So whatever is outside the channel (but inside the blockMesh background domain) is not of interest. The patches and walls have to defined inside the network of channel. Please help! Thanks a lot in advance!

  • Barış Bicer

    Moderator
    September 3, 2023 at 8:36 am

    Hi Borah,

    this is not big problem if I can understand your channel boundaries ok? If you are solving a channel internal flow, when you are creating your channel .stl please define the patch names correctly (inlet, outlet and walls etc..). and then snappyHexMesh will create these patches separately when it is applied. After that you should go to 3/polyMesh/boundary file to check the patch type where walls should be wall whereas inlet and outlet should be patch…

    I hope you understood. If you didnt understand please share your channel geometry with your patch name and setup.

    Good luck!!!

Log in to reply.

error: Content is protected !!