Voronoi tessellation

[sidharthsarmah]

Hi @GiudGiud ,

I want to create a voronoi tessellation of a steel sample and perform diffusion modelling. It has different types of grains and grain boundaries, I dont find lot of text related to VT in MOOSE, can you please suggest.

[GiudGiud]

Hello

There are plenty of options. See the PropertyReadFile to be able to load data using a voronoi distribution. Then once this data is in a FUnction you can use it to assign subdomains, (through FunctionAux + CoupledVarSubdomainModifier), to assign material properties (using the same PropertyReadFile) etc

[GiudGiud]

Are these equations supposed to be block restricted?

[sidharthsarmah]

Hi @GiudGiud, this is the overall picture, There are grains and grain boundaries, and each has its diffusivity.

[GiudGiud]

and each has its diffusivity.

if each grain has a different diffusivity, then they should on different subdomains because material properties are assigned on a per subdomain basis.

To split the mesh, I would recommend creating a subdomain modifier that assigns subdomains based on the VT loaded by the PropertyReadFile

[sidharthsarmah]

Hi @GiudGiud , I wish to proceed step by step:

1. I created a VT using Python code which gives x and y values of the 100 centres:

2. I inserted the file in MOOSE input:

a. But I dont see any grain boundary:

b. What is op_num = 25, does it mean 25 grains for 25 group of 100 grains generated, how are they assign?
c. I see some grains, say gr25, but no gr2, why?

[GiudGiud]

phase field order parameters are defined over the entire domain. there is no assignment of subdomains. They take a value of 1 where grain of "type" 25 is located, and 0 elsewhere. You should read the phase field documentation, notably the GrainTracker page