Hello everybody!

I was wondering if it is poosible to create graded meshes using multiple nested mesh blocks. The manual indicates that it is possible to nest ONE block mesh in another. Is it also possible to nest a block mesh in an already nested block mesh? Or is it generally not recommendable to build up such an hierarchic mesh structure?

(I am trying to handle HPDC-thin-walled casting parts)

Any comment is appreciated!

Regards m*

Hello, You can create as many nested-mesh blocks as you like however just remember that it will take more computational time. Best practice is to have fixed points aligning the mesh blocks and that the aspect ratios are no greater than 2.

Hi i believe multiple nested-block will introduced fluids volume conv error and eventually impact accuracy. so, better reduced number of nested blocks. Believe this is another major improvement needed by flow-3d.

Interesting. Never had that problem before. What version and how many nested blocks did you have when you got the fluids volume conv error and what percent of fluid volume conv error did you see?

i'm using v9.3.1 and max conv error is ~ 20% with 2 nested mesh blocks.

I wouldn't think nulti-nested blocks would increase the volume error. On the contrary, gradual change in the mesh size between consecutive blocks should improve accuracy and convergence. As MC pointed out, make sure each nested block fits within fixed mesh points in the containing block and the ratio of mesh size between any two adjacent blocks does not exceed 2.