[Isaiah_HZ]

Hi FOAMers,

Recently, I have been working on setting wind profile on inlet boundary, but I got a problem. That is, the actual wind profile appearing at paraFoam is not what I set by use of .csv file.

First file is my 0/U file

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 7
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
inlet
{
type fixedProfile;
profile csvFile;
profileCoeffs
{
nHeaderLine 0;
refColumn 0;
componentColumns (1 2 3);
separator ",";
mergeSeparators 0;
file "Uprofile.csv";
}
direction (0 1 0);
origin 0;
}

outlet
{
type inletOutlet;
inletValue uniform (0 0 0);
value uniform (0 0 0);
}

upperWall
{
type noSlip;
}

lowerWall
{
type noSlip;
}

frontAndBack
{
type empty;
}
}

second is my blockMeshDict

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 7
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices
(
(0 0 0)
(100 0 0)
(100 100 0)
(0 100 0)
(0 0 100)
(100 0 100)
(100 100 100)
(0 100 100)
);

blocks
(
hex (0 1 2 3 4 5 6 7) // vertex numbers
(100 100 1) // numbers of cells in each direction
simpleGrading (1 1 1) // cell expansion ratios
);

edges
(
);

boundary
(
inlet
{
type patch;
faces
(
(0 4 7 3)
);
}

outlet
{
type patch;
faces
(
(1 2 6 5)
);
}

upperWall
{
type wall;
faces
(
(5 6 7 4)
);
}

lowerWall
{
type wall;
faces
(
(0 3 2 1)
);
}

frontAndBack
{
type empty;
faces
(
(0 1 5 4)
(7 6 2 3)
);
}
);

third is my Uprofile.csv

0,0,0,0
1,4.521512266064,0,0
2,5.74080348822266,0,0
3,6.47518490182702,0,0
4,7.00237489142756,0,0
5,7.4139175417953,0,0
6,7.75153394393653,0,0
7,8.03778195361042,0,0
8,8.28624835323104,0,0
9,8.50575370016267,0,0
10,8.70235004129641,0,0
11,8.88037055420773,0,0
12,9.04302453212799,0,0
13,9.19275530770434,0,0
14,9.33146614031959,0,0
15,9.46066852117348,0,0
16,9.58158282629898,0,0
17,9.69520858664116,0,0
18,9.8023747569822,0,0
19,9.90377644888569,0,0
20,10.0000022788663,0,0
21,10.0915550696701,0,0
22,10.1788677537353,0,0
23,10.2623157542867,0,0
24,10.3422267406645,0,0
25,10.4188883990283,0,0
26,10.4925546840546,0,0
27,10.5634508945819,0,0
28,10.6317778290876,0,0
29,10.6977152141953,0,0
30,10.7614245536784,0,0
31,10.8230515116695,0,0
32,10.8827279185736,0,0
33,10.9405734691686,0,0
34,10.996697167891,0,0
35,11.0511985651711,0,0
36,11.1041688200513,0,0
37,11.1556916175805,0,0
38,11.2058439641673,0,0
39,11.2546968798716,0,0
40,11.3023160032561,0,0
41,11.3487621217236,0,0
42,11.3940916380935,0,0
43,11.4383569823987,0,0
44,11.4816069764453,0,0
45,11.5238871574916,0,0
46,11.5652400664264,0,0
47,11.6057055050204,0,0
48,11.6453207661477,0,0
49,11.6841208403179,0,0
50,11.722138601383,0,0
51,11.7594049738909,0,0
52,11.7959490842187,0,0
53,11.8317983973371,0,0
54,11.8669788408148,0,0
55,11.9015149174647,0,0
56,11.9354298078593,0,0
57,11.9687454637871,0,0
58,12.0014826935963,0,0
59,12.0336612402554,0,0
60,12.0652998528633,0,0
61,12.0964163522596,0,0
62,12.1270276913074,0,0
63,12.1571500103615,0,0
64,12.186798688375,0,0
65,12.2159883900497,0,0
66,12.2447331093923,0,0
67,12.2730462100005,0,0
68,12.3009404623686,0,0
69,12.3284280784738,0,0
70,12.3555207438783,0,0
71,12.3822296475565,0,0
72,12.40856550964,0,0
73,12.4345386072511,0,0
74,12.4601587985812,0,0
75,12.4854355453556,0,0
76,12.5103779338121,0,0
77,12.5349946943096,0,0
78,12.5592942196744,0,0
79,12.5832845823782,0,0
80,12.6069735506375,0,0
81,12.6303686035141,0,0
82,12.6534769450902,0,0
83,12.6763055177857,0,0
84,12.6988610148782,0,0
85,12.7211498922841,0,0
86,12.7431783796502,0,0
87,12.7649524908063,0,0
88,12.7864780336198,0,0
89,12.807760619295,0,0
90,12.8288056711531,0,0
91,12.8496184329277,0,0
92,12.8702039766075,0,0
93,12.8905672098554,0,0
94,12.9107128830314,0,0
95,12.930645595844,0,0
96,12.9503698036541,0,0
97,12.9698898234523,0,0
98,12.9892098395301,0,0
99,13.0083339088637,0,0

with those setup, I generated mesh and view mesh. when I plot velocity of inlet boundary condition, the velocity ranged from 2.26 to 13m/s instead of 0 to 13 m/s(please see attached pic). Can anyone help me explain it? Thank you very much!!!!!

[fumiya]

Hi,

I think you visualized the face center values.
A default interpolation scheme(linear) was used and you got (0 + 4.521512266064)/2=2.26.
So, I think the boundary condition works as expected.

Hope this helps,
Fumiya

[Isaiah_HZ]

Originally Posted by fumiya

Hi,

I think you visualized the face center values.
A default interpolation scheme(linear) was used and you got (0 + 4.521512266064)/2=2.26.
So, I think the boundary condition works as expected.

Hope this helps,
Fumiya

Thank you for your explanation.
However, when I checked velocity at different locations, they are different from what I have assigned. Do you have this problem before? Fumiya.

Hui

[fumiya]

Unfortunately, I've not used this boundary condition.
So, we need more information on what you wrote.

Best regards,
Fumiya

[Isaiah_HZ]

Originally Posted by fumiya

Unfortunately, I've not used this boundary condition.
So, we need more information on what you wrote.

Best regards,
Fumiya

Fumiya,

It would be very appreciated if you can provide some materials or links about this kind of boundary condition.

Best,
Hui

[ssa_cfd]

Did you try adding more points between 0 and 1 ?
Check the number of cells between 0 and 1 meters in paraview and add more points in the UProfile.csv

0,0,0,0
0.1,x,x,x
0.2,x,x,x
.
.
.
1,4.521512266064,0,0

I think it is just an interpolation problem.

[Isaiah_HZ]

Originally Posted by ssa_cfd

Did you try adding more points between 0 and 1 ?
Check the number of cells between 0 and 1 meters in paraview and add more points in the UProfile.csv

0,0,0,0
0.1,x,x,x
0.2,x,x,x
.
.
.
1,4.521512266064,0,0

I think it is just an interpolation problem.

Thank you, Ssa!
I will try! When I got any results, I will let you know and then we can talk about it.

Best,
Hui