Uniform Mesh for Circular Geometry in MOOSE

[sskalati]

Hi everyone,

I'm trying to simulate a circular geometry using the meshing tools built into MOOSE. I’ve written the following code using AnnularMeshGenerator

[Mesh]
  [msh]
    type = AnnularMeshGenerator
    nt = 1000
    rmax = 4.1e-3
    rmin = 0
    nr = 80
  []
[]

However, this results in very small elements near the center and progressively larger elements as the radius increases. What I actually need is a uniform mesh throughout the domain, where I can specify the element size directly for instance 0.1mm in my case (as shown in the attached figure).

Is there a way to achieve this in MOOSE? Any suggestions or alternative mesh generators that would work better?

Thanks in advance!

[GiudGiud]

Hello

There are a number of mesh generators that can do circular meshes.
The easiest for a uniform triangular one might be this one
https://mooseframework.inl.gov/source/meshgenerators/XYDelaunayGenerator.html
that would mesh inside a circular curve

This one makes a uniform quad mesh
https://mooseframework.inl.gov/source/meshgenerators/ConcentricCircleMeshGenerator.html
that you can then convert to triangles if you want using this
https://mooseframework.inl.gov/source/meshgenerators/ElementsToSimplicesConverter.html

[GiudGiud]

That is one option though you will also need to create the top and bottom surface meshes as well.

The extrusion can be done from a line mesh or from a sideset.

Alternatively, mesh in 2D then use the AdvancedExtruderGenerator to get a prism mesh

[BrankoK89]

Can I assign block_ids to any of these mesh generators? I need one with a block_id capability to assign materials

[GiudGiud]

some MGs have an option. Some you need to use the RenameBlockGenerator for

[BrankoK89]

Can I assign the outer boundary to any of these? None have it among their parameters. I am using PeripheralRingMeshGenerator around it and I need to know the input_mesh_external_boundary

[GiudGiud]

sometimes. Very few MGs will have an extra option to assign the outer boundary because it's usually not relevant to the MG operation.

If you see that parameter you can use it.
If not use this to assign the outer boundary. The sideset restriction parameters let you select that
https://mooseframework.inl.gov/source/meshgenerators/ParsedGenerateSideset.html