[CHUMMAR]

Hi .... I am new to openFOAM and i wanted to run a basic turbulent case using the hotroomboussinesq tutorial...... i wanted to implement that same turbulence properties into a blockmesh created by me. Is this possible. The files i changed for this were the '0' folder files, and the blockMeshDict file as :


scale 1;

vertices
(
(-0.2 0 -0.1)
( 1 0 -0.1)
( 1 1 -0.1)
(-0.2 1 -0.1)
(-0.2 0 0.1)
( 1 0 0.1)
( 1 1 0.1)
(-0.2 1 0.1)
);

blocks
(
hex (0 1 2 3 4 5 6 7) (48 40 8) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
top
{
type wall;
faces
(
(3 7 6 2)
);
}
hotwall
{
type patch;
faces
(
(0 4 7 3)
);
}
coldwall
{
type patch;
faces
(
(2 6 5 1)
);
}
bottom
{
type wall;
faces
(
(1 5 4 0)
);
}
back
{
type wall;
faces
(
(0 3 2 1)
);
}
front
{
type wall;
faces
(
(4 5 6 7)
);
}
);

mergePatchPairs
(
);



..............................................
from this :


convertToMeters 1;

vertices
(
(0 0 0)
(10 0 0)
(10 5 0)
(0 5 0)
(0 0 10)
(10 0 10)
(10 5 10)
(0 5 10)
);

blocks
(
hex (0 1 2 3 4 5 6 7) (20 10 20) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
floor
{
type wall;
faces
(
(1 5 4 0)
);
}
ceiling
{
type wall;
faces
(
(3 7 6 2)
);
}
fixedWalls
{
type wall;
faces
(
(0 4 7 3)
(2 6 5 1)
(0 3 2 1)
(4 5 6 7)
);
}
);

mergePatchPairs
(
);




Thank you

[CHUMMAR]

i made the polymesh file using salome-ideasUnvToFoam-checkMesh and got mesh non-orthonogality as 56.38. i am trying to obtain a turbulent analysis using buoyantPimpleFoam from the hotRoomBousinessq tutorial.


now after running pimpleFoam i am getting such an error message. Pls help

[Yann]

Hi Amal,

You have a fatal error stating the keyword div(((rho*nuEff)*dev2(T(grad(U))))) is missing in system/fvShemes. You need to add something like this in the divSchemes in the fvShemes file:

div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;

Cheers,
Yann

[CHUMMAR]

after using salome and finally giving checkMesh.......i edited the Allrun file and '#' out the blockMesh creation and straightly went for calling the application bouyantPimpleFoam. A log file is now gettting written but the case is not writing any time intervals. only the 0 folder is present and the logfile gets created after i give Allrun. Even if i edit the controlDict file for 1000 iterations with 100 writing interval nothing gets written . What is the issue now???



log file:
/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 7
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
Build : 7-1ff648926f77
Exec : buoyantPimpleFoam
Date : Jun 30 2022
Time : 08:28:22
Host : "chummar-GL553VE"
PID : 4565
I/O : uncollated
Case : /home/chummar/OpenFOAM/chummar-7/run/hotRoomBq
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


PIMPLE: No convergence criteria found


PIMPLE: Operating solver in transient mode with 1 outer corrector
PIMPLE: Operating solver in PISO mode


Reading thermophysical properties

Selecting thermodynamics package
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo eConst;
equationOfState Boussinesq;
specie specie;
energy sensibleInternalEnergy;
}

Reading field U

Reading/calculating face flux field phi

Creating turbulence model

Selecting turbulence model type RAS
Selecting RAS turbulence model kEpsilon
RAS
{
RASModel kEpsilon;
turbulence on;
printCoeffs on;
Cmu 0.09;
C1 1.44;
C2 1.92;
C3 0;
sigmak 1;
sigmaEps 1.3;
}


Reading g

Reading hRef
Calculating field g.h

Reading field p_rgh

Creating field dpdt

Creating field kinetic energy K

No MRF models present

Radiation model not active: radiationProperties not found
Selecting radiationModel none
No finite volume options present
Courant Number mean: 0 max: 0

Starting time loop

Courant Number mean: 0 max: 0
Time = 2

diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCGStab: Solving for Ux, Initial residual = 1, Final residual = 9.87889e-07, No Iterations 479


controlDict File:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 8
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application buoyantPimpleFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 1000;

deltaT 2;

writeControl adjustableRunTime;

writeInterval 100;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;

adjustTimeStep no;

maxCo 0.5;

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


thanks

[Yann]

Hi,

Can you post your full log file for buoyantPimpleFoam please?

Yann

[CHUMMAR]

Hi Yann,
I am sorry for the late reply. I was actually trying to edit the hotRoomBoussinesq case within the tutorials>heatTransfer>BuoyantPimpleFoam directory to view a turbulent heat transfer case within a differentially heated cube. I tried all things but finally when i simply ran the hotRoomBoussinesq tutorial case it was not writing case files at required intervals itself without any of my modifications. I then tried the hotRoom case and it was writing case files at correct intervals properly. So i then decided to edit the hotRoom case instead. Now i got it running and was able to see results in parafoam after running for 20000 iterations.



My problem now is i am able to get the temperature variation but i thought there would be variation for Ux and Uy within the differentially heated cubical enclosure but instead its showing zero. Do u know why?



I also have another very basic doubt.....When i run blockMeshDict and then checkMesh the mesh seems too coarse. how can i change it to a more medium or fine mesh.
I tried with salome>ideasUnvtoFoam and got a very good mesh but dont knw how to implement it into this case neglecting blockMesh.


Thankyou

[Yann]

Hi Amal,

Originally Posted by CHUMMAR

My problem now is i am able to get the temperature variation but i thought there would be variation for Ux and Uy within the differentially heated cubical enclosure but instead its showing zero. Do u know why?

I have no idea about what and how you modified the original case so I cannot really help if you don't share more details about the case you have run. (eg. setup files, log files, etc...)

Originally Posted by CHUMMAR

I also have another very basic doubt.....When i run blockMeshDict and then checkMesh the mesh seems too coarse. how can i change it to a more medium or fine mesh.
I tried with salome>ideasUnvtoFoam and got a very good mesh but dont knw how to implement it into this case neglecting blockMesh.

If you only want to refine the mesh, you can just modify the block(s) definition in blockMeshDict to had more cells: https://www.openfoam.com/documentati...ckmesh-utility