[Mirage12]

Hello everyone,

I am a new OpenFoam user and have tried to understand since 3 weeks, how OpenFoam is working. That's why i decided like to simulate a flow around cube and also cube natural convection and i hope that this topic will help the new user of OpenFoam.
I chose a cube because it is simple geometry, the solver

simpleFoam

for#Flow around cubeand the solver

buoyantPimpleFoam

for the #Cube natural convection.

I am not sure, if

buoyantPimpleFoam

is the right solver for the #Cube natural convection...

Here is my blockMeshDict-File

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

convertToMeters 0.1;

vertices
(
    (0 0 0)//0
    (1 0 0)//1
    (2 0 0)//2
    (3 0 0)//3
    (3 1 0)//4
    (3 2 0)//5
    (3 3 0)//6
    (2 3 0)//7
    (1 3 0)//8
    (0 3 0)//9
    (0 2 0)//10
    (0 1 0)//11
    (1 1 0)//12
    (2 1 0)//13
    (2 2 0)//14
    (1 2 0)//15
    (0 0 0.5)//16
    (1 0 0.5)//17
    (2 0 0.5)//18
    (3 0 0.5)//19
    (3 1 0.5)//20
    (3 2 0.5)//21
    (3 3 0.5)//22
    (2 3 0.5)//23
    (1 3 0.5)//24
    (0 3 0.5)//25
    (0 2 0.5)//26
    (0 1 0.5)//27
    (1 1 0.5)//28
    (2 1 0.5)//29
    (2 2 0.5)//30
    (1 2 0.5)//31
);


blocks
(
    hex (0 1 12 11 16 17 28 27) (20 20 10) simpleGrading (1 1 1) //1

    hex (1 2 13 12 17 18 29 28) (20 20 10) simpleGrading (1 1 1) //2

    hex (2 3 4 13 18 19 20 29) (20 20 10) simpleGrading (1 1 1) //3

    hex (13 4 5 14 29 20 21 30) (20 20 10) simpleGrading (1 1 1) //4

    hex (14 5 6 7 30 21 22 23) (20 20 10) simpleGrading (1 1 1) //5

    hex (15 14 7 8 31 30 23 24) (20 20 10) simpleGrading (1 1 1) //6 

    hex (10 15 8 9 26 31 24 25) (20 20 10) simpleGrading (1 1 1) //7

    hex (11 12 15 10 27 28 31 26) (20 20 10) simpleGrading (1 1 1) //8

);

edges
(


);
boundary
(
    outlet
    {
        type patch;
        faces
        ( 
            (3 4 20 19)
            (4 5 21 20)
            (5 6 22 21)
            
       
               
        );
    }
    inlet
    {
        type patch;
        faces
        (
          
           (9 10 26 25)
           (10 11 27 26)
           (11 0 16 27)
        );
    }
    fixedWalls
    {
        type wall;
        faces
        (
              (14 13 29 30)
              (12 15 31 28)
              (14 15 31 30)
              (12 13 29 28)
        );
    }
);

mergePatchPairs
(
);

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

I built the mesh using

blockMesh

and got this warning:

Creating block mesh topology
--> FOAM Warning : 
    From function polyMesh::polyMesh(... construct from shapes...)
    in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 901
    Found 22 undefined faces in mesh; adding to default patch.

but the meshing was good....i don't understand the meaning of the Warning. any idea ?



Than i typed

simpleFoam

in order to simulate the cflow around cube.



SimpleFoam seems to work :

Create time

Create mesh for time = 0

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting RAS turbulence model SpalartAllmaras
SpalartAllmarasCoeffs
{
    sigmaNut        0.66666;
    kappa           0.41;
    Cb1             0.1355;
    Cb2             0.622;
    Cw2             0.3;
    Cw3             2;
    Cv1             7.1;
    Cv2             5;
}

Creating finite volume options
No finite volume options present


SIMPLE: convergence criteria
    field p     tolerance 1e-05
    field U     tolerance 1e-05
    field nuTilda     tolerance 1e-05


Starting time loop

Time = 1

smoothSolver:  Solving for Ux, Initial residual = 1, Final residual = 0.0726962, No Iterations 2
GAMG:  Solving for p, Initial residual = 1, Final residual = 0.0521262, No Iterations 4
time step continuity errors : sum local = 3.66569, global = -2.27357e-13, cumulative = -2.27357e-13
smoothSolver:  Solving for nuTilda, Initial residual = 1, Final residual = 0.0803582, No Iterations 2
ExecutionTime = 0.84 s  ClockTime = 1 s

Time = 2

smoothSolver:  Solving for Ux, Initial residual = 0.651251, Final residual = 0.0381755, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.811213, Final residual = 0.0665551, No Iterations 2
time step continuity errors : sum local = 12.6457, global = -2.88632e-13, cumulative = -5.15989e-13
smoothSolver:  Solving for nuTilda, Initial residual = 0.268523, Final residual = 0.011164, No Iterations 4
ExecutionTime = 1.36 s  ClockTime = 1 s

Time = 3

smoothSolver:  Solving for Ux, Initial residual = 0.291545, Final residual = 0.0170455, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.78304, Final residual = 0.0427918, No Iterations 2
time step continuity errors : sum local = 16.3457, global = -1.55024e-13, cumulative = -6.71013e-13
smoothSolver:  Solving for nuTilda, Initial residual = 0.182843, Final residual = 0.0105602, No Iterations 4
ExecutionTime = 1.82 s  ClockTime = 2 s

Time = 4

smoothSolver:  Solving for Ux, Initial residual = 0.112318, Final residual = 0.00632812, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.580159, Final residual = 0.028626, No Iterations 2
time step continuity errors : sum local = 12.9383, global = -2.60342e-13, cumulative = -9.31355e-13
smoothSolver:  Solving for nuTilda, Initial residual = 0.158829, Final residual = 0.0102358, No Iterations 4
ExecutionTime = 2.29 s  ClockTime = 2 s

Time = 5

smoothSolver:  Solving for Ux, Initial residual = 0.21411, Final residual = 0.0126197, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.44336, Final residual = 0.0152502, No Iterations 2
time step continuity errors : sum local = 5.62188, global = -2.35846e-13, cumulative = -1.1672e-12
smoothSolver:  Solving for nuTilda, Initial residual = 0.146856, Final residual = 0.00996576, No Iterations 4
ExecutionTime = 2.82 s  ClockTime = 3 s

Time = 6

smoothSolver:  Solving for Ux, Initial residual = 0.240414, Final residual = 0.0148877, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.456608, Final residual = 0.0263508, No Iterations 2
time step continuity errors : sum local = 8.80232, global = -2.33654e-13, cumulative = -1.40086e-12
smoothSolver:  Solving for nuTilda, Initial residual = 0.14195, Final residual = 0.0100417, No Iterations 4
ExecutionTime = 3.31 s  ClockTime = 3 s

Time = 7

smoothSolver:  Solving for Ux, Initial residual = 0.126614, Final residual = 0.00789634, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.398651, Final residual = 0.0255971, No Iterations 2
time step continuity errors : sum local = 7.84955, global = -1.63525e-13, cumulative = -1.56438e-12
smoothSolver:  Solving for nuTilda, Initial residual = 0.139509, Final residual = 0.010145, No Iterations 4
ExecutionTime = 3.81 s  ClockTime = 4 s

Time = 8

smoothSolver:  Solving for Ux, Initial residual = 0.111525, Final residual = 0.0060335, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.338563, Final residual = 0.0178897, No Iterations 2
time step continuity errors : sum local = 5.31132, global = -1.2965e-13, cumulative = -1.69403e-12
smoothSolver:  Solving for nuTilda, Initial residual = 0.138472, Final residual = 0.0102371, No Iterations 4
ExecutionTime = 4.35 s  ClockTime = 4 s

Time = 9

smoothSolver:  Solving for Ux, Initial residual = 0.0770265, Final residual = 0.00430644, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.287078, Final residual = 0.0179152, No Iterations 2
time step continuity errors : sum local = 5.35135, global = -1.76606e-13, cumulative = -1.87064e-12
smoothSolver:  Solving for nuTilda, Initial residual = 0.138024, Final residual = 0.0103762, No Iterations 4
ExecutionTime = 4.81 s  ClockTime = 5 s

Time = 10

smoothSolver:  Solving for Ux, Initial residual = 0.053643, Final residual = 0.00339355, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.253213, Final residual = 0.014103, No Iterations 2
time step continuity errors : sum local = 4.29403, global = -2.67682e-13, cumulative = -2.13832e-12
smoothSolver:  Solving for nuTilda, Initial residual = 0.137795, Final residual = 0.0104911, No Iterations 4
ExecutionTime = 5.29 s  ClockTime = 5 s

End

and after running ParaView i got this Error:

ERROR: In /home/kitware/Dashboards/MyTests/ParaView-master/VTK/IO/vtkOpenFOAMReader.cxx, line 6882
vtkOpenFOAMReaderPrivate (0x1d9f0f0): boundaryField defaultFaces not found in object U at time = 0


ERROR: In /home/kitware/Dashboards/MyTests/ParaView-master/VTK/IO/vtkOpenFOAMReader.cxx, line 6882
vtkOpenFOAMReaderPrivate (0x1d9f0f0): boundaryField defaultFaces not found in object nuTilda at time = 0


ERROR: In /home/kitware/Dashboards/MyTests/ParaView-master/VTK/IO/vtkOpenFOAMReader.cxx, line 6882
vtkOpenFOAMReaderPrivate (0x1d9f0f0): boundaryField defaultFaces not found in object nut at time = 0


ERROR: In /home/kitware/Dashboards/MyTests/ParaView-master/VTK/IO/vtkOpenFOAMReader.cxx, line 6882
vtkOpenFOAMReaderPrivate (0x1d9f0f0): boundaryField defaultFaces not found in object p at time = 0

and that's why, i couldn't run the simulation....




do you have any idea, how to solve this problem ?



I need your Support



Thanks.