setfields for alpha
 

Dear Foamers,

I've created a geometry to simulate air injection into a tank filled with water as shown in the attached file.
I've also used the setFields to define the alpha in the system.
alpha =1 for the water inside the tank.
alpha =0 for the air in the injector (by suing the celltobox).

I have some problems with this. I could not define these alpha in my mesh. I think that I've missed something, after processing all the geometry is with alpha = 1 although using the celltobox with alpha = 0 !
Please could anyone help me ?

Thanks in advance !

Kind regards


// blockMesh : Block mesh description file
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
// ************************************
}






convertToMeters 1;

//5 mm column diameter
//10 cm length



//Width of middle square section




//how many cells in the square section
//how many cells from square section to perimeter
// how many cells from top to bottom

vertices
(

// partie cylindre sup
( 1.25 0.0 1.25) // Vertex fiveoclocksqb = 0
(-1.25 0.0 1.25) // Vertex sevenoclocksqb = 1
(-1.25 0.0 -1.25) // Vertex elevenoclocksqb = 2
( 1.25 0.0 -1.25) // Vertex oneoclocksqb = 3

( 1.76776695455285 0.0 1.76776695137989) // Vertex fiveoclockcb = 4
(-1.76776695455285 0.0 1.76776695137989) // Vertex sevenoclockcb = 5
(-1.76776695455285 0.0 -1.76776695137989) // Vertex elevenoclockcb = 6
( 1.76776695455285 0.0 -1.76776695137989) // Vertex oneoclockcb = 7

( 1.25 4 1.25) // Vertex fiveoclocksqt = 8
(-1.25 4 1.25) // Vertex sevenoclocksqt = 9
(-1.25 4 -1.25) // Vertex elevenoclocksqt = 10
( 1.25 4 -1.25) // Vertex oneoclocksqt = 11

( 1.76776695455285 4 1.76776695137989) // Vertex fiveoclockct = 12
(-1.76776695455285 4 1.76776695137989) // Vertex sevenoclockct = 13
(-1.76776695455285 4 -1.76776695137989) // Vertex elevenoclockct = 14
( 1.76776695455285 4 -1.76776695137989) // Vertex oneoclockct = 15

// partie injecteur

(-1.25 -2 0.11) // Vertex sevenoclockct = 16
(-1.75 -2 0.11) // Vertex elevenoclockct = 17
(-1.75 -2 -0.11) // Vertex sevenoclockct = 18
(-1.25 -2 -0.11) // Vertex elevenoclockct = 19

(-1.25 -2.22 0.11) // Vertex sevenoclockct = 20
(-1.75 -2.22 0.11) // Vertex elevenoclockct = 21
(-1.75 -2.22 -0.11) // Vertex sevenoclockct = 22
(-1.25 -2.22 -0.11) // Vertex elevenoclockct = 23

// partie cone
( 0.625 -2 0.625) // Vertex fiveoclocksqb = 24
(-0.625 -2 0.625) // Vertex sevenoclocksqb = 25
(-0.625 -2 -0.625) // Vertex elevenoclocksqb = 26
( 0.625 -2 -0.625) // Vertex oneoclocksqb = 27

( 0.88 -2 0.88) // Vertex fiveoclockcb = 28
(-0.88 -2 0.88) // Vertex sevenoclockcb = 29
(-0.88 -2 -0.88) // Vertex elevenoclockcb = 30
( 0.88 -2 -0.88) // Vertex oneoclockcb = 31

// partie cone bas (après injecteur) 1
( 0.625 -2.4 0.625) // Vertex fiveoclocksqb = 32
(-0.625 -2.4 0.625) // Vertex sevenoclocksqb = 33
(-0.625 -2.4 -0.625) // Vertex elevenoclocksqb = 34
( 0.625 -2.4 -0.625) // Vertex oneoclocksqb = 35

( 0.88 -2.4 0.88) // Vertex fiveoclockcb = 36
(-0.88 -2.4 0.88) // Vertex sevenoclockcb = 37
(-0.88 -2.4 -0.88) // Vertex elevenoclockcb = 38
( 0.88 -2.4 -0.88) // Vertex oneoclockcb = 39

// partie cone bas (après injecteur) 2
( 0.625 -2.22 0.625) // Vertex fiveoclocksqb = 40
(-0.625 -2.22 0.625) // Vertex sevenoclocksqb = 41
(-0.625 -2.22 -0.625) // Vertex elevenoclocksqb = 42
( 0.625 -2.22 -0.625) // Vertex oneoclocksqb = 43

( 0.88 -2.22 0.88) // Vertex fiveoclockcb = 44
(-0.88 -2.22 0.88) // Vertex sevenoclockcb = 45
(-0.88 -2.22 -0.88) // Vertex elevenoclockcb = 46
( 0.88 -2.22 -0.88) // Vertex oneoclockcb = 47
);

blocks
(

//square block
hex (
1 0 3 2
9 8 11 10
)
(10 10 5)
simpleGrading (1 1 1)

//slice1
hex (
5 4 0 1
13 12 8 9
)
(10 10 5)
simpleGrading (1 1 1)

//slice2
hex (
1 2 6 5
9 10 14 13
)
(10 10 5)
simpleGrading (1 1 1)

//slice3
hex (
2 3 7 6
10 11 15 14
)
(10 10 5)
simpleGrading (1 1 1)

//slice4
hex (
3 0 4 7
11 8 12 15
)
(10 10 5)
simpleGrading (1 1 1)



// cone
//square block
hex (
25 24 27 26
1 0 3 2
)
(10 10 5)
simpleGrading (1 1 1)
//slice1 bis
hex (
29 28 24 25
5 4 0 1
)
(10 10 5)
simpleGrading (1 1 1)
//slice2 bis
hex (
25 26 30 29
1 2 6 5
)
(10 10 5)
simpleGrading (1 1 1)
//slice3bis
hex (
26 27 31 30
2 3 7 6
)
(10 10 5)
simpleGrading (1 1 1)
//slice4bis
hex (
27 24 28 31
3 0 4 7
)
(10 10 5)
simpleGrading (1 1 1)


// cone bas (après injecteur)
//square block
hex (
33 32 35 34
41 40 43 42
)
(10 10 5)
simpleGrading (1 1 1)

//slice1
hex (
37 36 32 33
45 44 40 41
)
(10 10 5)
simpleGrading (1 1 1)
//slice2
hex (
33 34 38 37
41 42 46 45
)
(10 10 5)
simpleGrading (1 1 1)
//slice3
hex (
34 35 39 38
42 43 47 46
)
(10 10 5)
simpleGrading (1 1 1)
//slice4
hex (
35 32 36 39
43 40 44 47
)
(10 10 5)
simpleGrading (1 1 1)


// cone bas 2 (après injecteur)
//square block
hex (
41 40 43 42
25 24 27 26
)
(10 10 5)
simpleGrading (1 1 1)
//slice1
hex (
45 44 40 41
29 28 24 25
)
(10 10 5)
simpleGrading (1 1 1)
//slice2
hex (
41 42 46 45
25 26 30 29
)
(10 10 5)
simpleGrading (1 1 1)
//slice3
hex (
42 43 47 46
26 27 31 30
)
(10 10 5)
simpleGrading (1 1 1)
//slice4
hex (
43 40 44 47
27 24 28 31
)
(10 10 5)
simpleGrading (1 1 1)

//injecteur
hex (
21 20 16 17
22 23 19 18
)
(10 10 10)
simpleGrading (1 1 1)
);




//create the quarter circles
edges
(

// pour cylindre
arc 4 5 (0.0 0.0 2.5)
arc 5 6 (-2.5 0.0 0.0)
arc 6 7 (0.0 0.0 -2.5)
arc 7 4 (2.5 0.0 0.0)

arc 12 13 (0.0 4 2.5)
arc 13 14 (-2.5 4 0.0)
arc 14 15 (0.0 4 -2.5)
arc 15 12 (2.5 4 0.0)



// pour cone
arc 28 29 (0 -2 1.25)
arc 29 30 (-1.25 -2 0)
arc 30 31 (0 -2 -1.25)
arc 31 28 (1.25 -2 0)

// pour cone bas 1 après injecteur
arc 36 37 (0 -2.4 1.25)
arc 37 38 (-1.25 -2.4 0)

arc 38 39 (0 -2.4 -1.25)
arc 39 36 (1.25 -2.4 0)

// pour cone bas 2 après injecteur
arc 44 45 (0 -2.22 1.25)
arc 45 46 (-1.25 -2.22 0)

arc 46 47 (0 -2.22 -1.25)
arc 47 44 (1.25 -2.22 0)



/*
// pour injecteur
arc 16 19 (-2.5 0.40 0)
arc 16 20 (-2.5 0.56 0.16)
arc 20 23 (-2.5 0.72 0)
arc 23 19 (-2.5 0.56 -0.16)

arc 17 18 (-3 0.40 0)
arc 17 21 (-3 0.56 0.16)
arc 21 22 (-3 0.72 0)
arc 22 18 (-3 0.56 -0.16) */

);

boundary
(
inlet
{
type wall;
faces
(
(21 17 18 22)
);
}

leftWall
{
type wall;
faces
(
(37 45 46 38)
(45 29 30 46)
(5 13 14 6 )
);
}

rightWall
{
type wall;
faces
(
(36 28 31 39)
(28 4 7 31)
(4 12 15 7)
);
}

upperWall
{
type wall;
faces
(
(13 14 15 12)
);
}

lowerWall
{
type wall;
faces
(
(37 38 39 36)
);
}

frontAndBack
{
type empty;
faces
(
(17 21 20 16)
(18 22 23 19)

(37 45 44 36)
(38 46 47 39)

(45 29 28 44)
(46 30 31 47)

(29 5 4 28)
(30 6 7 31)

(5 13 12 4)
(6 14 15 7)
);
}
);

patches
(
);




for the setFields file :

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object setFieldsDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

defaultFieldValues
(
volScalarFieldValue alpha1 1
//volScalarFieldValue U (0 0 0)
);

regions
(
boxToCell
{
box (-1.75 -2.22 0.11) (-1.25 -2 -0.11);

fieldValues
(
volScalarFieldValue alpha1 0
);
}
);


// ************************************************** *********************** //


Thanks !

Krimo

If you attach archive of you case it'll be easier to figure out what is wrong. Also if you'd like to insert blockMeshDict and setFieldsDict in the post, please, use [CODE] tags.

You set the default value to 1 and, after that, alpha to 0 inside the box in setFieldsDict. If you want to invert it, invert these values in the dictionary.

Thanks for your reply Bernhardt, I tried your solutuion but it doesn't work.
In attached file the code source. Please if you have time you can check this problem.

Thanks in advance !

Kind regards

Krimo

In setFieldsDict you need to change this

to this

I think setFields doesn't like that Z of the first box point is higher than of the second.

DearAlexeym,

Excellent, now it works !
it's magic
Thank you very much for your help. I spent 3hours looking for this problem !
Again thank you very much

Kind regards

Krimo

May I know why dont you use ICEM or the others but blockMesh? blockMesh is not convenient dealing with this.

setFields
 

i want to design a nuzzle with cylinder ,what should i replace in setfieldsDict
(region)?sphereToCell or boxToCell?