CFD Online Discussion Forums - [snappyHexMesh] How to change patch types in snappyHexMesh?

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How to change patch types in snappyHexMesh?

Hi all,
I am meshing using snappyHexMesh for the first time.

I have a *.stl file wherein i have defined 3 solids - wall, inlet, outlet (those are the names given to the solids)

when running snappyHexMesh this is part of the output

Adding patches for surface regions
----------------------------------

Patch Type Region
----- ---- ------
xyz:

6 wall xyz_wall
7 wall xyz_inlet
8 wall xyz_outlet

Added patches in = 0.02 s

As you can see it has defined all the three boundaris as "wall" but inlet and outlet (of a pipe for example) are always defined as "patch". So how do i change the patch type of "inlet" and "outlet"?
Do i need to change only the boundary file in constant/polymesh? Or is there any other way to define it using snappyHexMesh - I saw something called as "patchInfo" in SHM but not sure how to use it to define different patch types to different boundaries.

Hi,

I just stumbled upon this post and think I know the answer, if it is still needed.

If you refer to https://github.com/OpenFOAM/OpenFOAM...ppyHexMeshDict you can see, that there is a patchInfo entry in "refinementsurfaces". If you don't set the patchInfo entry, SHM will refer to any given .stl-patch as "wall" by default.

So all you need to do is give it the patchInfo like this:

Code:



// Surface based refinement



    refinementSurfaces

    {

        yourStl.stl

        {

            // Surface-wise min and max refinement level

            level (2 2);



            // Optional specification of patch type (default is wall). No

            // constraint types (cyclic, symmetry) etc. are allowed.

            

            patchInfo

            {

                type patch;

            }



  

        }

    }

Hope that helps,
cheers!