Octree Overlaps in GridRefinement3D

#1

HI Communities,

I have met a problem when GridRefinement.
When I do a gridrefinement, let’s say 3 levels generated — 0 1 2. These Octrees can already consist the whole domain perfectly.
However, there will generate another Octree for lower level , let’s say it Level0 — Octree Overlap for Level0.

What make me confuse is that when I do lattice.getLevel(0), I find the lattice_tmp I got is that Octree Level0 + Octree Overlap for Level0. So, is the collide and stream procession will also be done in the whole domain of Octree Overlap for Level0? Or only the interface nodes in Octree Overlap for Level0 will be process when collide and stream?

In fact, when I check a cell in Octree Overlap for Level0, there exist some error.

Furthermore, if the nodes in Octree Overlap for Level0 are useless except interface ones, could I just get Octree Level0 by some command as lattice.getLevel()?

Waiting for your reply and really thanks,
Lyu

#2

Hello,
I’m not sure to understand your concern here.

For simplicity reasons there are overlap blocks that are created for grid refinement interfaces. These blocks are only here to allow a “simple” interface implementation but most of their cells are not used (contain only numerical noise). One should not try to print them or get any useful information from them expect on interface regions.

#3

Hi Orestis,

Very thanks for your kind reply.

‘most of their cells are not used (contain only numerical noise)’ does this means: when I use lattice.getLevel(), the lattice I get will not include these cells? Then all the info of this lattice I got can be use for other process.