Question about refining mesh in a cylindrical region

[RBstudentPhD]

Hi,

First of all, thank you for your amazing tool!

I'm trying to mesh a cylindrical domain with a finer mesh inside a smaller cylindrical region within the domain.

I define my domain as follows:
$NEPER -T -n 1000 -domain "cylinder(h,d,100)" -reg 1 -o mesh_RS
In this example, the cylinder is centered at x=d/2, y=d/2 with a radius of d/2.

I would like to generate a mesh where the region inside a smaller cylinder (centered at x=d/2, y=d/2, radius r, and height between z=z1 and z=z2) is a times finer than at the outer regions of the domain.

I believe this can be done using the -rcl option:
$NEPER -M mesh_RS.tess -rcl "?????????" -o mesh_RS -nset faces -format inp,vtk,msh
From what I understand, this involves using tessellation keys with the -rcl option, but I’m having trouble figuring out the correct syntax.

I also would like to add that the command "-nset faces" doesn't seem to be working, unless I used it wrong. No nset appear in the mesh files.

Could you please provide the appropriate command or an example?
Thank you in advance,
Best regards,
Rémy

[rquey]

The most general approach is to export the cell centroids, and then define the element size based on whether a cell belongs to the inner cylinder or not.

Here is a simple example:

neper -T -n 100 -reg 1 -statcell x,y,z
awk '{if ($3<0.5) {print "0.2"} else {print "1.0"}}' n100-id1.stcell  > rcl
neper -M n100-id1.tess -rcl "file(rcl)"
neper -V n100-id1.tess,n100-id1.msh -print d

rcl can also be defined at the face, edge or vertex level...