Hi all
I'm trying to replicate the results of this paper:
https://www.sciencedirect.com/scienc...60132316300208
It uses a slightly adapted solver (
https://link.springer.com/article/10...546-008-9325-7) which I believe I've implemented correctly into OpenFOAM.
Here's a simple schematic of the 2D problem:
https://i.imgur.com/3DPE4yo.png
I've tried using groovyBC to set a gradient and just using fixedGradient to get heat transfer across the red patch. Here's my 0/T file:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v1612+ |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 0 0 1 0 0 0];
internalField uniform 300;
boundaryField
{
floor
{
type fixedValue;
value uniform 300;
}
hotWall
{
type groovyBC;
value uniform 300;
valueExpression "300";
gradientExpression "gradT";
fractionExpression "0";
variables
(
"heatFlux=37;"
"rho=1.2;"
"cp=1.0;"
"nutemp=1.0e-5;"
"pr=0.9;"
"kappa=nutemp/pr;"
"gradT=heatFlux/((kappa+alphat)*rho*cp);"
);
// evaluateDuringConstruction true;
}
ceiling
{
type inletOutlet;
inletValue uniform 300;
value uniform 300;
}
fixedWallsX1
{
type symmetry;
}
fixedWallsX2
{
type inletOutlet;
inletValue uniform 300;
value uniform 300;
}
defaultFaces
{
type empty;
}
}
// ************************************************************************* //
However, when I run, the temperature in the domain remains unchanged. In paraView I see some high temperature areas in the cells across the red face, however, there's never any diffusion of temperature or the expected buoyant velocities forming.
Here are the steps I have taken:
I thought perhaps I'd implemented the T equation incorrectly, so I tried using setFields to create a high temperature area in the middle of the domain. This behaved as normally, causing vertical perturbations and the high temperature diffused.
I also thought perhaps the BC itself wasn't working. I modified the hotRoom tutorial to have the same groovyBC and ran it with my custom solver, but the effects of the temperature gradient are quite obvious.
I thought perhaps my mesh was the issue, as that's the main difference between the modified hotRoom and this case. Here is my blockMesh:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: plus |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
convertToMeters 1000;
vertices
(
(0 0 0)//0
(10 0 0)//1
(10 1 0)//2
(0 1 0)//3
(0 0 3)//4
(10 0 3)//5
(10 1 3)//6
(0 1 3)//7
);
blocks
(
hex (0 1 2 3 4 5 6 7) (37 1 150) simpleGrading (1 1 1436)
);
edges
(
);
boundary
(
floor
{
type wall;
faces
(
(0 3 2 1)
);
}
ceiling
{
type patch;
faces
(
(4 5 6 7)
);
}
fixedWallsX1
{
type symmetry;
faces
(
(0 4 7 3)
);
}
fixedWallsX2
{
type patch;
faces
(
(1 5 6 2)
);
}
);
mergePatchPairs
(
);
// ************************************************************************* //
(I create the hotWall patch using topoSet and createPatch afterwards)
I've tried applying the BC to the ceiling and the right hand outlet and when I execute, the case rapidly explodes, so it's clearly doing something. I thought perhaps the issue was to do with the hotWall patch not working correctly, so I just applied the groovyBC to the floor instead and nothing happens.
Here are my fvSchemes and fvSolutions:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: plus |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
solvers
{
p
{
solver PCG;
preconditioner DIC;
tolerance 1e-3;
relTol 0;
}
pFinal
{
$p;
relTol 0;
tolerance 1e-3;
}
U
{
solver PBiCGStab;
preconditioner DILU;
tolerance 1e-3;
relTol 0;
}
UFinal
{
$U;
relTol 0;
tolerance 1e-3;
}
"(T|k|epsilon|R)"
{
solver PBiCGStab;
preconditioner DILU;
tolerance 1e-3;
relTol 0;
}
"(T|k|epsilon|R)Final"
{
$U;
relTol 0;
tolerance 1e-3;
}
}
PIMPLE
{
momentumPredictor yes;
nOuterCorrectors 1;
nCorrectors 2;
nNonOrthogonalCorrectors 0;
pRefCell 0;
pRefValue 0;
residualControl
{
U
{
tolerance 1e-3;
relTol 0;
}
p
{
tolerance 1e-3;
relTol 0;
}
T
{
tolerance 1e-3;
relTol 0;
}
k
{
tolerance 1e-3;
relTol 0;
}
epsilon
{
tolerance 1e-3;
relTol 0;
}
R
{
tolerance 1e-3;
relTol 0;
}
}
}
relaxationFactors
{
equations
{
"(U|T|k|epsilon|R)" 1;
"(U|T|k|epsilon|R)Final" 1;
}
}
// ************************************************************************* //
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: plus |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
ddtSchemes
{
default Euler;
}
gradSchemes
{
default Gauss linear;
}
divSchemes
{
default none;
div(phi,U) Gauss upwind;
div(phi,T) Gauss linear;
div(phi,k) Gauss upwind;
div(phi,epsilon) Gauss upwind;
div((nuEff*dev2(T(grad(U))))) Gauss linear;
}
laplacianSchemes
{
default Gauss linear corrected;
laplacian(nuEff,U) Gauss linear corrected;
laplacian((1|A(U)),p) Gauss linear corrected;
laplacian(alphaEff,T) Gauss linear corrected;
laplacian(DkEff,k) Gauss linear corrected;
laplacian(DepsilonEff,epsilon) Gauss linear corrected;
laplacian(DREff,R) Gauss linear corrected;
}
interpolationSchemes
{
default linear;
}
snGradSchemes
{
default uncorrected;
}
// ************************************************************************* //
So I feel that it is something to do with the mesh, but I am really not sure what. I've tried removing the grading, increasing and decreasing resolution, but nothing seems to help it function properly.
Does anyone have any experience with this? Can provide any other information needed
Cheers
