Question about the numbers of mesh cells

ASPECT
1

Hello,

I have some questions about the mesh.

After watching the 2020 tectonics modeling tutorial video, I tried to run the tutorial.prm file from Day 1.

The following is about the grid settings.

subsection Mesh refinement
  set Initial global refinement                = 3
  set Initial adaptive refinement              = 0
  set Time steps between mesh refinement       = 0
end

I believe the model has 64 mesh cells, and this is confirmed in the statistics and the log.txt file.

Number of active cells: 64 (on 4 levels)
Number of degrees of freedom: 948 (578+81+289)

However, when I use ParaView to open the solution.pvd file, I see more than 64 mesh cells.

image
image990Ă—572 47.4 KB

How is the actual mesh resolution？

2

Hi Haolin,

ASPECT has an input parameter called “set Interpolate output” and the default is true. This means that in the graphical output, you don’t just see the verticies of each mesh cell, but additional points based on the polynomial degree of finite elements ASPECT uses for the velocity (by default, that is 2 – see also the documentation of that input parameter).

Best,
Juliane

1 Like
3

Hi Juliane,

Thank you for your attention and prompt reply! I understand this issue now.