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-   -   Could someone tell me what boxToCell means (https://www.cfd-online.com/Forums/openfoam-pre-processing/60995-could-someone-tell-me-what-boxtocell-means.html)

 dan March 28, 2006 06:57

Could someone tell me what boxToCell means

I get one queation in the dambreak tutorial of interFoam.
The setFieldsDict are shown below:
regions
(
boxToCell
{
box (0 0 -1) (0.1461 0.292 1);

fieldValues
(
volScalarFieldValue gamma 1
);
}
);

What does "box (0 0 -1) (0.1461 0.292 1)" mean?

In this case ,I don't see anything related to (0 0 -1) and (0.1461 0.292 1).
Could anyone help me,thanks?

 hartinger March 28, 2006 08:18

It specifies two opposite poin

It specifies two opposite points of a box. All cells within that box are selected. It is used to set the void fraction gamma, in order to pile up a lot of water to be splash around.

markus

 eugene March 28, 2006 08:19

"box (0 0 -1) (0.1461 0.292 1)

"box (0 0 -1) (0.1461 0.292 1)"
defines a rectangular prism aligned with the coordinate system with one point (minimum x, y and z) at (0 0 -1) and another point (maximum x, y and z) at (0.1461 0.292 1).

 dan March 28, 2006 21:24

Thank you all. But something c

Thank you all. But something confused me is why is "box (0 0 -1) (0.1461 0.292 1)" in this case.
eg:
convertToMeters 0.146
0.1461*0.146=0.0213 is not the physical size of water column.
So does 0.292,1,and -1.
Could anyone help me,thanks?

 hartinger March 29, 2006 07:05

The 'convertToMeters' in block

The 'convertToMeters' in blockMeshDict is only used inside the 'blockMesh' mesh-generator. x=0.1461 and y=0.292 is the 'top-right' corner of the water column in physical space. The other coordinates are just chosen to be bigger for convenience

markus

 dan March 29, 2006 21:17

Thanks,I already know it. There is a geometry figure in the uer guide U-55, it is different with the simulated case. So I am just a little confused. Thank you.

 ronaldo October 21, 2009 09:33

1 Attachment(s)
Quote:
 Originally Posted by eugene (Post 186725) "box (0 0 -1) (0.1461 0.292 1)" defines a rectangular prism aligned with the coordinate system with one point (minimum x, y and z) at (0 0 -1) and another point (maximum x, y and z) at (0.1461 0.292 1).

Please could you tell me how can i set the makeCellSets file "boxToCell" is case?

 avillamizarh May 5, 2013 01:55

Zmin y Zmax

Quote:
 Originally Posted by dan (Post 186726) Thank you all. But something confused me is why is "box (0 0 -1) (0.1461 0.292 1)" in this case. eg: convertToMeters 0.146 0.1461*0.146=0.0213 is not the physical size of water column. So does 0.292,1,and -1. Could anyone help me,thanks?

I have a question. Why the zmin is -1 and zmax is 1?. Thanks

 Parisa_Khiabani September 3, 2014 14:44

I have 2 questions about setFields. I was partially answered based on the the following post:

http://www.cfd-online.com/Forums/ope...ell-means.html

However, my questions are:

1- How the minimum and maximum corners are determined?

2- Why zmin and zmax are -1 and +1, as exactly the last forumer aske?

I appreciate if you help me,

Parisa

 wyldckat September 28, 2014 11:28

1. Quote:
 Originally Posted by wyldckat (Post 457771) Have a look into this file: https://github.com/OpenFOAM/OpenFOAM...et/topoSetDict You can find it on your system by running: Code: `find \$FOAM_UTILITIES  -name topoSetDict` But keep in mind that if your internal mesh isn't already cut into the shape of the sphere, then all you get is a selection of the cells that are inside the sphere selection.
2. Quote:
 Originally Posted by wyldckat (Post 353511) It's simple: setSet and topoSet are basically selection tools that can select parts of the mesh, including points, faces and cells. Once you select parts of the mesh and assign each selection a "tag" (i.e. a "set"), then you can do something with that "tag".

 nb977 February 17, 2016 16:26

Hello ,
i need help regarding those 2 lines
what is the difference between add and new , and is it true that openFoam no longer use cellSet should i replace it with something else ?

cellSet refine new
cellSet refine add boxToCell (0.0 0.0 0.0) (0.584 0.146 0.584)
cellSet refine new boxToCell (0.0 0.146 0.0) (0.548 0.292 0.584)

Thank you

 wyldckat February 21, 2016 13:56

Quote:
 Originally Posted by nb977 (Post 585744) what is the difference between add and new
• "new" is for creating a new set.

Quote:
 Originally Posted by nb977 (Post 585744) and is it true that openFoam no longer use cellSet should i replace it with something else ?
You're mixing up two things:
1. There was an application named "cellSet" in older versions of OpenFOAM.
2. The current setSet application has a command named "cellSet", which is still working. The lines you pointed out should work within setSet.
For more details: http://openfoamwiki.net/index.php/SetSet#Usage_example

 nb977 February 22, 2016 20:17

Thank you very much i am now able to refine the region i wanted !

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