Creating irregular rectangular lattices

User Support
1

Hi all,

This is a question related to this thread, and the attached github question. Is there a way to create irregularly shaped periodic lattices without having to resort to what’s suggested in the github reply? I ask because although that solution is strictly the “true” periodicity of the lattice, It would be nice to be able to create irregular periodic universes such that a fuel assembly could be modelled properly as one universe (ie, without having to split one FA into multiple universes).

My original idea was to construct normal rectangular lattices, and then to create a cell inside the universe that is being intruded into by the adjacent universe that corresponds to the region of the intruding universe that is actually inside of the intruded universe, and to fill that cell with the intruding universe, but that didn’t work (i assume because regions of a universe that extend outside of the lattice pitch are discarded?).

Is there a way to do this?

Thanks,
James

2

No, unfortunately as you’ve found, the universe filling a lattice position will effectively get “chopped off” at the boundaries of the lattice. The only lattices that are supported at present at rectangular lattices and hexagonal lattices. If you have some other type of lattice, you either have to cast it into one of those forms or explicitly model individual cells in lieu of using lattices altogether.

3

Thanks Paul, do you think it would be possible to create a lattice-like structure out of cells that are shaped like the FA’s, fill (then translate) them with the FA universes? (is that what you meant by “explicitly model individual cells in lieu of using lattices”?)

Thanks again for your help!

4

Yes, cells can be filled with universes (with an arbitrary translation/rotation specified), so that would probably be your best bet.

1 Like