[spwater]

Hello:
Recently I am working on chtMultiRegionFoam and start with the planeWall2D case.

https://openfoamwiki.net/index.php/G..._-_planeWall2D

Though it won't work directly with the latest OF, it is still a good beginning to understand the structure of the case.
Here is my question, when I am looking at the system/bottomAir/changeDictionaryDict:
1, why is there a
boundary
{
bottomAir_bottom
{
type symmetryPlane;
}
}
at beginning? I see the defination repeated in all the following variable's defination, like U.

2, what does ".*" means, does that mean all solid boundary, or somethign else? As I see "bottomAir_to_.*" means baffles between bottomAir and solid region wall.

3, why there is no ".*" boundary in U but in p, and no "bottomAir_to_.*" boundary in p but in U?

yours

Pei

[Pappelau]

hello pei



For Question 2 : these are regular Expressions (Google RegEx) ".*" means ALL boundarys in the region "bc_xy_.*" means all boundarys that begin with bc_xy_ ... as example
What directly leads to 3 : for p all boundarys get the same condition so u use just ".*"
as example.... U you need different conditions for different boundarys so no ".*"


cheers

[spwater]

Thank you Pappelau!

Originally Posted by Pappelau

hello pei



For Question 2 : these are regular Expressions (Google RegEx) ".*" means ALL boundarys in the region "bc_xy_.*" means all boundarys that begin with bc_xy_ ... as example
What directly leads to 3 : for p all boundarys get the same condition so u use just ".*"
as example.... U you need different conditions for different boundarys so no ".*"


cheers

[Yann]

Hi Pei,

Regarding your first question: in this tutorial, changeDictionary is used to define all the boundary conditions.

For each regions you have a changeDictionaryDict file. When changeDictionary is executed it basically edit all the files in the 0 directory with the proper boundary conditions.

You could get the same result by defining the boundary conditions right away in the 0 directory.

Cheers,
Yann