Subdomain from a cylinder

[HemiaoZhang]

Hi MOOSE community,

I am generating 1/4 of a cylinder using the script below,

[Mesh]
   [concentric_circle]
       type = ConcentricCircleMeshGenerator
       num_sectors = 6
       radii = '18.5'
       rings = '4'
       has_outer_square = off
       portion = top_right
       preserve_volumes = off
       smoothing_max_it = 3
   []
   [extrude]
       type = MeshExtruderGenerator
       extrusion_vector = '0 0 75'
       num_layers = 15
       bottom_sideset = 'bottom'
       top_sideset = 'top'
       input = concentric_circle
   []
   [rotate]
       type = TransformGenerator
       transform = ROTATE
       vector_value = '0 270 0'
       input = extrude
   []
[]

However, the back and bottom sidesets are both defined under 'bottom'.

I tried 'SubdomainBoundingBoxGenerator' as suggested by some previous discussions but couldn't separately define a 'back', i.e., y>0, and true 'bottom', i.e., y=0.

Is there any other way to separate the current bottom sideset?

Many thanks!

[GiudGiud]

Hello

If you change the input to this

[Mesh]
   [concentric_circle]
       type = ConcentricCircleMeshGenerator
       num_sectors = 6
       radii = '18.5'
       rings = '4'
       has_outer_square = off
       portion = top_right
       preserve_volumes = off
       smoothing_max_it = 3
       show_info = true
   []
   [extrude]
       type = MeshExtruderGenerator
       extrusion_vector = '0 0 75'
       num_layers = 15
       bottom_sideset = 'low_Z'
       top_sideset = 'top'
       input = concentric_circle
   []
   [rotate]
       type = TransformGenerator
       transform = ROTATE
       vector_value = '0 270 0'
       input = extrude
   []
[]

you ll see that concentric_circle is already using the name 'bottom', so extrude is creating an additional bottom region, here renamed to low_Z to prevent that

[HemiaoZhang]

It works! Now the bottom wedge is named under 'low_z' and the side is named under 'bottom'. Many thanks Guillaume!

[HemiaoZhang]

Just a follow-up question. I want to choose a point as a nodeset from the generated cylinder follow the discussion on #28869. However, I got the following error message.

[Mesh]
    [concentric_circle]
        type = ConcentricCircleMeshGenerator
        num_sectors = 6
        radii = '18.5'
        rings = '4'
        has_outer_square = off
        #portion = top_right
        preserve_volumes = off
        smoothing_max_it = 3
        show_info = true
    []
    [extrude]
        type = MeshExtruderGenerator
        extrusion_vector = '0 0 75'
        num_layers = 15
        bottom_sideset = 'low_Z'
        top_sideset = 'top'
        input = concentric_circle
    []
    [rotate]
        type = TransformGenerator
        transform = ROTATE
        vector_value = '0 270 0'
        input = extrude
    []
    [bottom_center_node]
        type = ParsedGenerateNodeset
        input = rotate
        expression = '(abs(x) < 1e-12) & (abs(y) < 1e-12) & (abs(z) < 1e-12)'
        new_nodeset_name = 'bottom_center'
    []
[]

*** ERROR ***
A 'ParsedGenerateNodeset' is not a registered object.

If you are trying to find this object in a dynamically loaded library, make sure that
the library can be found either in your "Problem/library_path" parameter or in the
MOOSE_LIBRARY_PATH environment variable.

[GiudGiud]

Hello

How old is your version of moose?
This object is about 6 months old iirc

Guillaume

[HemiaoZhang]

it’s pretty old. I plan to update it once I finish the current project. Is there any alternative to select a point as nodeset to apply boundary conditions? Sent from mobile. Please excuse brevity.

…

________________________________ Von: Guillaume Giudicelli ***@***.***> Gesendet: Monday, May 19, 2025 4:16:06 AM An: idaholab/moose ***@***.***> Cc: HemiaoZhang ***@***.***>; Author ***@***.***> Betreff: Re: [idaholab/moose] Subdomain from a cylinder (Discussion #30532) Hello How old is your version of moose? This object is about 6 months old iirc Guillaume — Reply to this email directly, view it on GitHub<#30532 (reply in thread)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/APAO3XQNNVV5GVRJWX4DIE327G4PNAVCNFSM6AAAAAB5LA3H2KVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGMJZGI2TQNA>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[GiudGiud]

ok then people usually use this object instead to make a tiny box around the node of interest

https://mooseframework.inl.gov/source/meshgenerators/BoundingBoxNodeSetGenerator.html

[GiudGiud]

this object is really old, it will be included in your version

[HemiaoZhang]

It works! Many thanks again!