How to Achieve Mesh Refinement Only in the Y-Direction in Pelec?

[yjh124]

I am looking to generate a mesh with refinement only in the y-direction (as shown in Figure 1). However, after checking the functionality of Pelec, I noticed that it currently only supports mesh refinement simultaneously in the x, y, and z directions (i.e., full 3D refinement).
Could anyone please advise if there are alternative methods or workarounds to achieve mesh refinement restricted exclusively to the y-direction in Pelec?
Any guidance, code snippets, or references to relevant documentation would be greatly appreciated!

[baperry2]

There is not a way to add AMR levels in only one direction in PeleC and the grid on each level must be uniform, so it is not possible to achieve a grid similar to the one you have pictured with existing capability in PeleC. However, for cases without embedded boundaries, you can use an anisotropic base grid, so you can set the base resolution in the y direction to be smaller than the x and z directions, which may be helpful in your case. See #853 and #964.

[yjh124]

Thank you very much for your reply! I’ve noticed that PeleC generates meshes using initialize_EB2, which in turn relies on amrex::EB2::Build for mesh construction.
In this scenario, am I correct to assume that we cannot utilize amrex’s anisotropic refinement parameter ref_ratio_vect? Additionally, could you also advise how to completely avoid using EB2 for mesh generation?

[baperry2]

A slight clarification, PeleC generates the embedded boundary data through those routines, but the cartesian mesh is generated through other AMReX routines.

For cases with EB, we do not permit dx != dy != dz anyway, so anisotropic refinement would be difficult to support. If the geometry is all_regular (no EB in domain), the EB geometry generation doesn't do anything and this should probably be ok. But IDK what else might need to change to enable anisotropic refinement without EB.