[aspect-devel] The input for limiting the mesh refinement area

[Juliane Dannberg]

Hi Nan,

I think there are plugins called "Minimum refinement function" and 
"Maximum refinement function" that allow you to set a minimum and 
maximum level of refinement as function of, for example, the radius. 
Maybe this is what you are looking for? The syntax is:

subsection Mesh refinement
   set Strategy                                 = temperature, maximum 
refinement function

   subsection Maximum refinement function
     set Coordinate system      = spherical
     set Function constants     =
     set Function expression    = 6 + 
2*sin((r+250000)*2*pi/250000)*sin(12*phi)
     set Variable names         = r,phi
   end
end

Best,
Juliane


On 01/27/2016 08:36 PM, Wolfgang Bangerth wrote:
>
> Nan,
>
>> I try to limit the mesh refinement to a 3D spherical cap within a global
>> spherical shell. More specifically, What I want is that, given 4 
>> points on the
>> Earth surface and 2 depths, the refinement will be limited in this 
>> spherical
>> cap. If I remembered correctly, Timo had done this two years ago?
>>
>> When I tried to find this input information, I grep mesh refinement 
>> boundary.
>> I found something like "Boundary refinement indicators" in
>> tests/refinement_boundary.prm. While, it is under "set Strategy = 
>> boundary". I
>> am not sure this is what I want, because I still want "set Strategy =
>> temperature".
>>
>> I wonder how to set up the space limit for the mesh refinement?
>
> I don't think there's a plugin that already does what you want to do. 
> But it shouldn't be very difficult to write one.
>
> There are two kinds of mesh refinement plugins:
> - Ones that compute error indicators; these are run first, and you 
> already have the one that you want, namely the temperature one
> - Ones that run second and that add or remove refinement and 
> coarsening flags. You will want to write one of this kind that simply 
> removes the refinement flags in all of those areas that you don't care 
> about.
>
> Take a look at those refinement plugins that define a function 
> tag_additional_cells() to get an idea of how to do what you want.
>
> Best
>  W.
>
>