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-   -   chtMultiRegionSimpleFoam: maximum number of iterations excedeed. (https://www.cfd-online.com/Forums/openfoam-solving/166264-chtmultiregionsimplefoam-maximum-number-iterations-excedeed.html)

Nkl February 5, 2016 10:45
chtMultiRegionSimpleFoam: maximum number of iterations excedeed.
 
Hi everyone.

I am trying to simulate a case with chtMultiRegionSimpleFoam. I have two solid regions and one fluid region.
This is the error message that i get when i try to run the case.

Code:
Time = 1


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 1, Final residual = 0.002480292, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 1, Final residual = 0.03671355, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.9999997, Final residual = 0.01561736, No Iterations 1
Min/max T:562.9999 563
GAMG:  Solving for p_rgh, Initial residual = 0.9999924, Final residual = 0.008730997, No Iterations 6
time step continuity errors : sum local = 20506.89, global = 26.95327, cumulative = 26.95327
Min/max rho:1871.519 1871.519
DILUPBiCG:  Solving for epsilon, Initial residual = 0.09139717, Final residual = 0.0005513963, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 1, Final residual = 0.02256889, No Iterations 1

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.5280382, Final residual = 0.001258966, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.3690461, Final residual = 0.002262562, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1604709, Final residual = 0.0009344701, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1126575, Final residual = 0.0007983021, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08671032, Final residual = 0.0007140963, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09292769, Final residual = 0.0007248033, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1074406, Final residual = 0.0007217357, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08790488, Final residual = 0.0006937387, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08910365, Final residual = 0.0006455751, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1082888, Final residual = 0.000716009, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08564961, Final residual = 0.0007132726, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09113913, Final residual = 0.0006894596, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1045455, Final residual = 0.0006481019, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08687302, Final residual = 0.0006629876, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08842034, Final residual = 0.0006584863, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1070657, Final residual = 0.0006447156, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08507228, Final residual = 0.0006544767, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09051075, Final residual = 0.0006668173, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051791, Final residual = 0.0006743241, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.0865891, Final residual = 0.0006571282, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08850392, Final residual = 0.0006297229, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1072329, Final residual = 0.0006522072, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 0.22 s  ClockTime = 0 s

Time = 2


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.8748544, Final residual = 0.01853232, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.6139603, Final residual = 0.006541587, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.9839853, Final residual = 0.09201838, No Iterations 1
Min/max T:-1294.7 2492.159
GAMG:  Solving for p_rgh, Initial residual = 0.9988731, Final residual = 0.002823299, No Iterations 2
time step continuity errors : sum local = 1.13883e+07, global = -14690.11, cumulative = -14663.16
Min/max rho:1800 2000
DILUPBiCG:  Solving for epsilon, Initial residual = 0.2557687, Final residual = 0.001599441, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.7537869, Final residual = 0.004870482, No Iterations 1

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.1426549, Final residual = 0.000527261, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.08523395, Final residual = 0.0006670678, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09039161, Final residual = 0.0006447351, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1052049, Final residual = 0.0006316827, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08715248, Final residual = 0.0006589468, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08851995, Final residual = 0.0006325161, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.107094, Final residual = 0.0006640415, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08470138, Final residual = 0.000640998, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09057836, Final residual = 0.0006554425, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051921, Final residual = 0.0006551075, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.0865938, Final residual = 0.0006458004, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.0886378, Final residual = 0.0006173178, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1077172, Final residual = 0.0006610182, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08484742, Final residual = 0.0006648984, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09022893, Final residual = 0.0006424737, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051718, Final residual = 0.0006476323, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08702445, Final residual = 0.0006426613, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08855915, Final residual = 0.0006607156, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1069757, Final residual = 0.0006330477, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08519058, Final residual = 0.0006546551, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09064632, Final residual = 0.0006672477, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051225, Final residual = 0.0006524659, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 0.27 s  ClockTime = 0 s

Time = 3


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.01074519, Final residual = 3.067248e-05, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.04582875, Final residual = 0.0003332501, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.2011091, Final residual = 0.00402989, No Iterations 1


--> FOAM FATAL ERROR:
Maximum number of iterations exceeded

    From function thermo<Thermo, Type>::T(scalar f, scalar T0, scalar (thermo<Thermo, Type>::*F)(const scalar) const, scalar (thermo<Thermo, Type>::*dFdT)(const scalar) const, scalar (thermo<Thermo, Type>::*limit)(const scalar) const) const
    in file /home/openfoam/OpenFOAM/OpenFOAM-2.3.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 76.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>::THs(double, double, double) const at ??:?
#3  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::polynomialTransport<Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>, 8> > >::calculate() at ??:?
#4  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::polynomialTransport<Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>, 8> > >::correct() at ??:?
#5 
 at ??:?
#6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#7 
 at ??:?
Annullato (core dump creato)
And this is my controlDict file:

Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                |                                                |
| \\      /  F ield        | OpenFOAM: The Open Source CFD Toolbox          |
|  \\    /  O peration    | Version:  2.3.1                                |
|  \\  /    A nd          | Web:      www.OpenFOAM.org                      |
|    \\/    M anipulation  |                                                |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version    2.0;
    format      ascii;
    class      dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application    chtMultiRegionSimpleFoam;

startFrom      startTime;

startTime      0;

stopAt          endTime;

endTime        50000;

deltaT          1;

writeControl    timeStep;

writeInterval  100;

purgeWrite      5;

writeFormat    ascii;

writePrecision  7;

writeCompression uncompressed;

timeFormat      general;

timePrecision  6;

runTimeModifiable true;


// ************************************************************************* //
Thanks in advance for the help!

zfaraday February 5, 2016 13:46
Hi Nikola,

Well, more information is needed in order to be able to help you, take a look at this thread! For instance, information regarding the BC's would come in handy!

A few comments about your case:
  • The temperature of the fluid region undergoes an excessive change from the first time step to the second one.
    Code:
    Min/max T:562.9999 563 ---> Min/max T:-1294.7 2492.159
    Of course, it crashes after this time step since you are reaching negative temperatures! You should check your fvSoution specification.
  • A lot of "nNonOrthogonalCorrectors" are used for the wall2 region, whereas no one is used for the wall1 region. This is not necessary a mistake, it depends on your case; however, it may be a little shocking such a difference from a region to another

However, as I said before, it is totally impossible to give you a hand without the minimum required information since we don't know what your case is about.

Best regards,

Alex

Nkl February 9, 2016 05:34
Hi and thanks! Here is the link to my case:

https://www.dropbox.com/sh/0urwdyk35...wVgQUdLUa?dl=0

In this moment I am trying to figure out as well why foam says that my mesh is inconsistent - when I got the "maximum number of iterations error" I was employing a different mesh.
Here is the blockMeshDict file of the liquid region, I don't see any inconsistency:

Code:
/*--------------------------------*- C++ -*----------------------------------*\
| =========                |                                                |
| \\      /  F ield        | OpenFOAM: The Open Source CFD Toolbox          |
|  \\    /  O peration    | Version:  2.3.1                                |
|  \\  /    A nd          | Web:      www.OpenFOAM.org                      |
|    \\/    M anipulation  |                                                |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version    2.0;
    format      ascii;
    class      dictionary;
    object      blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 0.001;

vertices
(
    (0 0 0)
    (24.35 0 0)
    (26 0 0)
    (28.50 0 0)
    (0 250 0)
    (24.35 250 0)
    (26 250 0)
    (28.50 250 0)
    (0 10250 0)
    (24.35 10250 0)
    (26 10250 0)
    (28.50 10250 0)
    (24.35 10471.50 0)
    (26 10471.50 0)
    (28.50 10471.50 0)
    (0 10495.20 0)
    (0 10496.85 0)
    (0 10498.35 0)
    (0 0 0.3)
    (24.35 0 0.3)
    (26 0 0.3)
    (28.50 0 0.3)
    (0 250 0.3)
    (24.35 250 0.3)
    (26 250 0.3)
    (28.50 250 0.3)
    (0 10250 0.3)
    (24.35 10250 0.3)
    (26 10250 0.3)
    (28.50 10250 0.3)
    (24.35 10471.50 0.3)
    (26 10471.50 0.3)
    (28.50 10471.50 0.3)
    (0 10495.20 0.3)
    (0 10496.85 0.3)
    (0 10498.35 0.3)
);

blocks
(
    hex (0 1 5 4 18 19 23 22) (24 250 1) simpleGrading (1 1 1)
    hex (2 3 7 6 20 21 25 24) (2 250 1) simpleGrading (1 1 1)
    hex (4 5 9 8 22 23 27 26) (24 100 1) simpleGrading (1 1 1)
    hex (6 7 11 10 24 25 29 28) (2 100 1) simpleGrading (1 1 1)
    hex (8 9 12 15 26 27 30 33) (24 245 1) simpleGrading (1 1 1)
    hex (10 11 14 13 28 29 32 31) (2 221 1) simpleGrading (1 1 1)
    hex (12 13 16 15 30 31 34 33) (2 26 1) simpleGrading (1 1 1)
    hex (13 14 17 16 31 32 35 34) (2 28 1) simpleGrading (1 1 1)
);

edges
(
    arc 15 12 (17.21805012 10488.71805 0)
    arc 33 30 (17.21805012 10488.71805 0.3)
    arc 16 13 (18.38477631 10489.88478 0)
    arc 34 31 (18.38477631 10489.88478 0.3)   
    arc 17 14 (20.152543226 10491.65254326 0)
    arc 35 32 (20.152543226 10491.65254326 0.3) 
);

boundary
(
    inlet
    {
        type patch;
        faces
        (
            (2 3 21 20)
        );
    }
    outlet
    {
        type patch;
        faces
        (
            (0 1 19 18)
        );
    }
    walls
    {
        type wall;
        faces
        (
            (1 5 23 19)
            (5 9 27 23)
            (9 12 30 27)
            (12 13 31 30)
            (13 10 28 31)
            (10 6 24 28)
            (6 2 20 24)
            (3 7 25 21)
            (7 11 29 25)
            (11 14 32 29)
            (14 17 35 32)
        );
    }
    left
    {
        type symmetryPlane;
        faces
        (
            (4 0 18 22)
            (8 4 22 26)
            (15 8 26 33)
            (16 15 33 34)
            (17 16 34 35) 
        );
    }
    frontAndBack
    {
        type empty;
        faces
        (
            (0 4 5 1)
            (2 6 7 3)
            (4 8 9 5)
            (6 10 11 7)
            (8 15 12 9)
            (10 13 14 11)
            (12 15 16 13)
            (13 16 17 14)
            (18 22 23 19)
            (20 24 25 21)
            (22 26 27 23)
            (24 28 29 25)
            (26 33 30 27)
            (28 31 32 29)
            (30 33 34 31)
            (31 34 35 32)
        );
    }       
);

mergePatchPairs
(
);

// ************************************************************************* //
Thanks in advance!

zfaraday February 9, 2016 12:12
Hi Nikola,

First of all, please, take a look at this thread in order to ask your questions correctly. I have no time to invest in running your case and find your mistakes for you. However, if you attach your log file with the error message I will be able to see what is going wrong.

By the way, have you checked your mesh with checkMesh utility?

Best regards,

Alex

Nkl February 9, 2016 12:20
Hi,

Ok, i guess the entire case is too general, sorry.

As I wrote in the second question I have modified the geometry of a region, but when I run blockMesh it says there is a block inconsistency. I've posted my blockMeshDict file. After I fix that, I will run the case again, post a screen of the geometry and send you the error log. Do you know how do I solve the block inconsistency problem?

Thanks again.

zfaraday February 9, 2016 12:24
Quote:
Originally Posted by Nkl (Post 584384)
Hi,

Ok, i guess the entire case is too general, sorry.

As I wrote in the second question I have modified the geometry of a region, but when I run blockMesh it says there is a block inconsistency. I've posted my blockMeshDict file. After I fix that, I will run the case again, post a screen of the geometry and send you the error log. Do you know how do I solve the block inconsistency problem?

Thanks again.
In order to diagnose the inconsistency I should see the error message, it usally points you to the cause of your problem.

Nkl February 9, 2016 12:27
I didn't specify cause from what I searched it is a common error depending on the number of cells of the blocks. I tried to change many times the values, to me it seems to make sense.
Here is the error message I get:

Code:
Create time


Generating mesh for region moltenSalt
Creating block mesh from
    "/home/nikola/OpenFOAM/nikola-2.3.1/run/PhD/receiverMultiRegion2/constant/moltenSalt/polyMesh/blockMeshDict"
Creating curved edges
Creating topology blocks
Creating topology patches

Creating block mesh topology

Check topology

        Basic statistics
                Number of internal faces : 7
                Number of boundary faces : 34
                Number of defined boundary faces : 34
                Number of undefined boundary faces : 0
        Checking patch -> block consistency

Creating block offsets
Creating merge list

--> FOAM FATAL ERROR:
Inconsistent number of faces between block pair 4 and 6

    From function blockMesh::calcMergeInfo()
    in file blockMesh/blockMeshMerge.C at line 221.

FOAM exiting

zfaraday February 9, 2016 12:43
Great! Here we can start looking for something...

Look at these lines
Code:
--> FOAM FATAL ERROR:
Inconsistent number of faces between block pair 4 and 6
It leads you to the blocks labeled as 4 and 6. Now you have to go back to the blockMeshDict file and find them out! Which is easy, if the geometry has been generated with the same blockMeshDict specification as you gave some posts above these blocks are
Code:
blocks
(
    hex (0 1 5 4 18 19 23 22) (24 250 1) simpleGrading (1 1 1)
    hex (2 3 7 6 20 21 25 24) (2 250 1) simpleGrading (1 1 1)
    hex (4 5 9 8 22 23 27 26) (24 100 1) simpleGrading (1 1 1)
    hex (6 7 11 10 24 25 29 28) (2 100 1) simpleGrading (1 1 1)
    hex (8 9 12 15 26 27 30 33) (24 245 1) simpleGrading (1 1 1)
    hex (10 11 14 13 28 29 32 31) (2 221 1) simpleGrading (1 1 1)
    hex (12 13 16 15 30 31 34 33) (2 26 1) simpleGrading (1 1 1)
    hex (13 14 17 16 31 32 35 34) (2 28 1) simpleGrading (1 1 1)
);
Check the block divisions that I marked in bold, it seems not to be very consistent... According to the error message, these two blocks have a common face in contact (I haven't spent any second to figure out what the overall geometry looks like) and the block division in each block face must be consistent!

Hope it helps!

Alex

Nkl February 9, 2016 12:51
Thanks, but I already tried to change the values to these blocks but it doesn't seem to work.
The contact face is a semi-circular one. I set the number of cells in order that each one is 1mm x 1mm.

zfaraday February 9, 2016 12:57
Quote:
Originally Posted by Nkl (Post 584391)
Thanks, but I already tried to change the values to these blocks but it doesn't seem to work.
The contact face is a semi-circular one. I set the number of cells in order that each one is 1mm x 1mm.
But you cannot change these values in a random manner. If two blocks have a common face, these two faces have to be divided into the same number of faces. Check again the numbers I marked in bold in my previous post!

Nkl February 9, 2016 18:18
I know i cannot change the numbers in a random way and i know they need to have the same number of faces. The problem is that the semi-circular surface, which is the border between the two blocks, is not orthogonal to the axis. How do I determine the number of cells in this case?

zfaraday February 9, 2016 20:39
Quote:
Originally Posted by Nkl (Post 584431)
I know i cannot change the numbers in a random way and i know they need to have the same number of faces. The problem is that the semi-circular surface, which is the border between the two blocks, is not orthogonal to the axis. How do I determine the number of cells in this case?
The same way you would do it in any other case... Check out the User Guide to find the answer!

Nkl February 10, 2016 07:31
I am sorry for the too many posts and the incorrect way of asking questions.
I fixed the mesh and checkMesh seems to work properly for all the three regions.
Here are the log files:

https://www.dropbox.com/s/q78uoqq72g...nSalt.log?dl=0
https://www.dropbox.com/s/dhx7oobzm3...wall1.log?dl=0
https://www.dropbox.com/s/z57ivq9iul...wall2.log?dl=0

When I run the solver 'chtMultiRegionSimpleFoam' I get this error message after 3 iterations:

Code:
Time = 1


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 1, Final residual = 0.002825982, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 1, Final residual = 0.04132034, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.9999996, Final residual = 0.0154298, No Iterations 1
Min/max T:562.9994 563.0009
GAMG:  Solving for p_rgh, Initial residual = 0.9999889, Final residual = 0.004834167, No Iterations 6
GAMG:  Solving for p_rgh, Initial residual = 0.002394688, Final residual = 2.371736e-05, No Iterations 65
GAMG:  Solving for p_rgh, Initial residual = 2.341292e-05, Final residual = 1.514739e-06, No Iterations 1000
GAMG:  Solving for p_rgh, Initial residual = 1.535508e-06, Final residual = 9.919197e-08, No Iterations 563
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.923936e-08, Final residual = 9.923936e-08, No Iterations 0
time step continuity errors : sum local = 0.4699706, global = 0.0009671473, cumulative = 0.0009671473
Min/max rho:1871.518 1871.519
DILUPBiCG:  Solving for epsilon, Initial residual = 0.06467489, Final residual = 0.001771638, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 1, Final residual = 0.09235881, No Iterations 1

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.5280382, Final residual = 0.001258966, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.3690461, Final residual = 0.002262562, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1604709, Final residual = 0.0009344701, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1126575, Final residual = 0.0007983021, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08671032, Final residual = 0.0007140963, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09292769, Final residual = 0.0007248033, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1074406, Final residual = 0.0007217357, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08790488, Final residual = 0.0006937387, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08910365, Final residual = 0.0006455751, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1082888, Final residual = 0.000716009, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08564961, Final residual = 0.0007132726, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09113913, Final residual = 0.0006894596, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1045455, Final residual = 0.0006481019, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08687302, Final residual = 0.0006629876, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08842034, Final residual = 0.0006584863, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1070657, Final residual = 0.0006447156, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08507228, Final residual = 0.0006544767, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09051075, Final residual = 0.0006668173, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051791, Final residual = 0.0006743241, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.0865891, Final residual = 0.0006571282, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08850392, Final residual = 0.0006297229, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1072329, Final residual = 0.0006522072, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 2.54 s  ClockTime = 3 s

Time = 2


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.872695, Final residual = 0.02930037, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.2661313, Final residual = 0.02074659, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.9749577, Final residual = 0.005849796, No Iterations 2
Min/max T:-884.8169 3257.34
GAMG:  Solving for p_rgh, Initial residual = 0.9985905, Final residual = 0.002927187, No Iterations 2
GAMG:  Solving for p_rgh, Initial residual = 0.003673249, Final residual = 3.331033e-05, No Iterations 5
GAMG:  Solving for p_rgh, Initial residual = 3.330113e-05, Final residual = 3.290616e-07, No Iterations 783
GAMG:  Solving for p_rgh, Initial residual = 3.290705e-07, Final residual = 9.974295e-08, No Iterations 440
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.974231e-08, Final residual = 9.974231e-08, No Iterations 0
time step continuity errors : sum local = 304.0205, global = 1.367212, cumulative = 1.368179
Min/max rho:1800 2000
DILUPBiCG:  Solving for epsilon, Initial residual = 0.1267599, Final residual = 0.009777908, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.5708649, Final residual = 0.02911266, No Iterations 1

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.1426549, Final residual = 0.000527261, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.08523395, Final residual = 0.0006670678, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09039161, Final residual = 0.0006447351, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1052049, Final residual = 0.0006316827, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08715248, Final residual = 0.0006589468, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08851995, Final residual = 0.0006325161, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.107094, Final residual = 0.0006640415, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08470138, Final residual = 0.000640998, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09057836, Final residual = 0.0006554425, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051921, Final residual = 0.0006551075, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.0865938, Final residual = 0.0006458004, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.0886378, Final residual = 0.0006173178, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1077172, Final residual = 0.0006610182, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08484742, Final residual = 0.0006648984, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09022893, Final residual = 0.0006424737, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051718, Final residual = 0.0006476323, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08702445, Final residual = 0.0006426613, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08855915, Final residual = 0.0006607156, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1069757, Final residual = 0.0006330477, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.08519058, Final residual = 0.0006546551, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.09064632, Final residual = 0.0006672477, No Iterations 1
DICPCG:  Solving for h, Initial residual = 0.1051225, Final residual = 0.0006524659, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 4.34 s  ClockTime = 5 s

Time = 3


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.02314685, Final residual = 0.0005031902, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.08500071, Final residual = 0.0024218, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.06128905, Final residual = 0.0003700965, No Iterations 1


--> FOAM FATAL ERROR:
Maximum number of iterations exceeded

    From function thermo<Thermo, Type>::T(scalar f, scalar T0, scalar (thermo<Thermo, Type>::*F)(const scalar) const, scalar (thermo<Thermo, Type>::*dFdT)(const scalar) const, scalar (thermo<Thermo, Type>::*limit)(const scalar) const) const
    in file /home/openfoam/OpenFOAM/OpenFOAM-2.3.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 76.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>::THs(double, double, double) const at ??:?
#3  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::polynomialTransport<Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>, 8> > >::calculate() at ??:?
#4  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::polynomialTransport<Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>, 8> > >::correct() at ??:?
#5 
 at ??:?
#6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#7 
 at ??:?
Annullato (core dump creato)
Since the mesh seems to be ok I guess the problem is in the fvSolution and fvSchemes files. I took them from a similar multiRegion tutorial case since I am new to OpenFoam.

Here are the files

moltenSalt region:

https://www.dropbox.com/s/3gl4leenps...fvSchemes?dl=0
https://www.dropbox.com/s/jw7fqxh7to...vSolution?dl=0

wall regions:
https://www.dropbox.com/s/fzxdzsi2l8...fvSchemes?dl=0
https://www.dropbox.com/s/zr2snw4qdm...vSolution?dl=0

I hope I didn't post too many things again. Thanks and sorry again!

Nkl February 15, 2016 06:46
Anybody could help?

jmdf February 16, 2016 05:24
Hi,

have you tried to lower the relaxation factor of h?
As the temperatures blow up on the second iteration, it might help.

I don't know if you tested it already :p

Nkl February 16, 2016 10:19
Thanks. I lowered the relaxation factor for h from 0.7 to 0.3. The solver now reaches time=5 but then crashes again. This is the fatal error I get:

Code:
Time = 1


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 1, Final residual = 0.0003264315, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 1, Final residual = 0.005378647, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.9999952, Final residual = 0.000984237, No Iterations 1
Min/max T:562.9999 563.0001
GAMG:  Solving for p_rgh, Initial residual = 0.9999951, Final residual = 0.005289151, No Iterations 6
GAMG:  Solving for p_rgh, Initial residual = 0.002618408, Final residual = 2.607994e-05, No Iterations 68
GAMG:  Solving for p_rgh, Initial residual = 2.575757e-05, Final residual = 6.033973e-07, No Iterations 1000
GAMG:  Solving for p_rgh, Initial residual = 6.117042e-07, Final residual = 9.858678e-08, No Iterations 533
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.86257e-08, Final residual = 9.86257e-08, No Iterations 0
time step continuity errors : sum local = 0.4605076, global = 8.085596e-05, cumulative = 8.085596e-05
Min/max rho:1871.519 1871.519
DILUPBiCG:  Solving for epsilon, Initial residual = 0.06521978, Final residual = 0.001787177, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 1, Final residual = 0.07889281, No Iterations 1

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.5101815, Final residual = 0.0001297209, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.5112915, Final residual = 0.0002025927, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 2.59 s  ClockTime = 3 s

Time = 2


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.6445604, Final residual = 0.0019006, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.07135245, Final residual = 0.0007496466, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.9083394, Final residual = 0.01430983, No Iterations 1
Min/max T:35.65297 1889.626
GAMG:  Solving for p_rgh, Initial residual = 0.9998192, Final residual = 0.002216853, No Iterations 2
GAMG:  Solving for p_rgh, Initial residual = 0.007889519, Final residual = 7.822511e-05, No Iterations 6
GAMG:  Solving for p_rgh, Initial residual = 7.824874e-05, Final residual = 7.810568e-07, No Iterations 261
GAMG:  Solving for p_rgh, Initial residual = 7.811e-07, Final residual = 9.961736e-08, No Iterations 904
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.961807e-08, Final residual = 9.961807e-08, No Iterations 0
time step continuity errors : sum local = 75.72265, global = -0.5355312, cumulative = -0.5354504
Min/max rho:1800 2000
DILUPBiCG:  Solving for epsilon, Initial residual = 0.1176014, Final residual = 0.01003929, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.485968, Final residual = 0.003753748, No Iterations 2

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.2623717, Final residual = 5.387229e-05, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.1440557, Final residual = 8.869466e-05, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 4.28 s  ClockTime = 5 s

Time = 3


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.0006579773, Final residual = 6.510305e-07, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.002377684, Final residual = 1.232516e-05, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.04466604, Final residual = 2.46947e-05, No Iterations 1
Min/max T:112.0722 1815.252
GAMG:  Solving for p_rgh, Initial residual = 0.9977593, Final residual = 0.003774196, No Iterations 2
GAMG:  Solving for p_rgh, Initial residual = 0.001897838, Final residual = 1.867311e-05, No Iterations 337
GAMG:  Solving for p_rgh, Initial residual = 1.862081e-05, Final residual = 2.786867e-06, No Iterations 1000
GAMG:  Solving for p_rgh, Initial residual = 2.783504e-06, Final residual = 1.293305e-07, No Iterations 1000
GAMG:  Solving for p_rgh, Initial residual = 1.293191e-07, Final residual = 9.987048e-08, No Iterations 18
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.987045e-08, Final residual = 9.987045e-08, No Iterations 0
time step continuity errors : sum local = 119.8354, global = -0.4635982, cumulative = -0.9990486
Min/max rho:1800 2000
DILUPBiCG:  Solving for epsilon, Initial residual = 0.04836913, Final residual = 0.001498709, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.3789519, Final residual = 0.002761163, No Iterations 2

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.09316923, Final residual = 2.737059e-05, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.07516395, Final residual = 4.386694e-05, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 7.64 s  ClockTime = 8 s

Time = 4


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.765953, Final residual = 0.008731101, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.2308538, Final residual = 0.001827885, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.999978, Final residual = 0.01399727, No Iterations 1
Min/max T:-102136.9 93478.23
GAMG:  Solving for p_rgh, Initial residual = 0.9999905, Final residual = 8.936352e-06, No Iterations 1
GAMG:  Solving for p_rgh, Initial residual = 2.701559e-05, Final residual = 2.408767e-07, No Iterations 19
GAMG:  Solving for p_rgh, Initial residual = 2.408695e-07, Final residual = 9.989073e-08, No Iterations 314
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
GAMG:  Solving for p_rgh, Initial residual = 9.98878e-08, Final residual = 9.98878e-08, No Iterations 0
time step continuity errors : sum local = 52216.37, global = 81.95447, cumulative = 80.95542
Min/max rho:1800 2000
DILUPBiCG:  Solving for epsilon, Initial residual = 0.5315941, Final residual = 0.01739989, No Iterations 1
DILUPBiCG:  Solving for k, Initial residual = 0.8941032, Final residual = 0.008152165, No Iterations 1
bounding k, min: -22430.99 max: 1283287 average: 13658.63

Solving for solid region wall1
DICPCG:  Solving for h, Initial residual = 0.05225653, Final residual = 9.536828e-06, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 563 max(T) [0 0 0 1 0 0 0] 563

Solving for solid region wall2
DICPCG:  Solving for h, Initial residual = 0.04101362, Final residual = 2.849273e-05, No Iterations 1
Min/max T:min(T) [0 0 0 1 0 0 0] 873 max(T) [0 0 0 1 0 0 0] 873
ExecutionTime = 8.16 s  ClockTime = 9 s

Time = 5


Solving for fluid region moltenSalt
DILUPBiCG:  Solving for Ux, Initial residual = 0.005961712, Final residual = 6.706337e-08, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.07593738, Final residual = 0.0001346784, No Iterations 1
DILUPBiCG:  Solving for h, Initial residual = 0.001921711, Final residual = 7.76007e-06, No Iterations 1


--> FOAM FATAL ERROR:
Maximum number of iterations exceeded

    From function thermo<Thermo, Type>::T(scalar f, scalar T0, scalar (thermo<Thermo, Type>::*F)(const scalar) const, scalar (thermo<Thermo, Type>::*dFdT)(const scalar) const, scalar (thermo<Thermo, Type>::*limit)(const scalar) const) const
    in file /home/openfoam/OpenFOAM/OpenFOAM-2.3.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 76.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>::THs(double, double, double) const at ??:?
#3  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::polynomialTransport<Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>, 8> > >::calculate() at ??:?
#4  Foam::heRhoThermo<Foam::rhoThermo, Foam::pureMixture<Foam::polynomialTransport<Foam::species::thermo<Foam::hPolynomialThermo<Foam::icoPolynomial<Foam::specie, 8>, 8>, Foam::sensibleEnthalpy>, 8> > >::correct() at ??:?
#5 
 at ??:?
#6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#7 
 at ??:?
Annullato (core dump creato)

karlli February 16, 2016 10:46
Dear Nikola,
It seems that you have done the common mistake of trying to do too much in one step without ensuring you have a working, intermediate case first. I strongly advise you to start with something really basic (like the planeWall2D tutorial) and build on it step by step so that you are able to understand why a certain step causes the simulation to crash. This will save you a lot of headache working with OF. If you did start from a simpler case, it would be useful to know at which stage you started experiencing problems :)

Nevertheless, here are some hints on things to consider for the case you posted earlier:
  • The grid has an extreme jump in y-resolution close to the top and bottom of your domain. This will lead to nasty numerical errors (e.g. in gradient computations). Use some kind of grading in the y-direction, or use a more homogeneous spacing of grid points.
  • The viscosity is large and very nonlinear with temperature. This will introduce some strong coupling effects between the thermal field and the flow field. Start by getting a converged solution for constant properties before adding property variations with temperature (this also goes for the other properties, which look quite nonlinear)
  • A strong under-relaxation for U is normally needed, in my experience. Try 0.3 rather than 0.7
  • Finally, it seems that you have defined the inlet velocity in the wrong direction? Should it not be along the y-axis?
Hope this helps,

Best regards,
Karl

olivierG February 16, 2016 10:54
hello,

Your fluid temperature goes to dumb value.
You may have either bad BC, bad initialisation value for T,or excessive heat source somewhere.
So:
1) check your BC (every BC, even turbulence file ...). This is where 60-80% mistake are made.
2) Try to initialize with a better guess of the solution
3) If you have heat source: try to relax source
4) if you still in trouble at start-up, use a higher value for conductivity in your fluid (10 to 100 higher), then come back to the correct one after 10-50 iter.
And lower this crazy high number of pressure orthogonal iteration.

regards,
olivier

Nkl February 16, 2016 11:42
Thanks for the suggestions!

To Karl:

- I did start with Plane Wall 2D, but it seems it was not enough.
- What you are saying regarding Y-plus values is true. This is because in the y direction the domain is 10.5 meters long, so in the middle I used extremely large cells in order to reduce the computational time. That could be a problem, I guess.
- I lowered the relaxation factor for U and corrected the velocity, that was a distraction. Thanks!

To Olivier:

- Thanks for the tips, I'll check again all my BC. Regarding the pressure orthogonal iteration I took the value from another Heat Transfer tutorial case using chtMultiRegionSimpleFoam. I'll lower it btw.

Vishsel October 10, 2019 02:42
Iterations for h running double the time
 
1 Attachment(s)
Hi all,

I am using chtMultiRegionSimpleFoam solver. I have both solid and fluid region. And i have to create heat flux on the wall of the solid body.

for my case, i just run the solver & I checked the convergence plot at 500 iterations, in that solving for 'h' alone running double the time. May i know what error it is ??

I have attached the plot picture.


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