[titanchao]

Can I use fvOptions to couple a solid region and a fluid region?


The solid region represents a porous medium. The reason I want to do the coupling is because I need to solve both the thermal energy transport in the fluid and the heat conduction in the porous medium. I intend to use the chtMultiRegionSimpleFoam solver.



(1) Is fvOptions allowed to be used to couple two regions that have different governing equations?


(2) I modified the settings based on the heat exchanger case in the tutorial. Because I want a heat conduction equation to be solved for my porous region (vs. another flow region in the original tutorial case), I modified the fvSchems file to one that's supposed to solve a Laplacian equation only (see the following). Is this correct?

FoamFile
{
version 2.0;
format ascii;
class dictionary;
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
default steadyState;//Euler;
}

gradSchemes
{
default Gauss linear;
grad(T) Gauss linear;
}

divSchemes
{
default none;
}

laplacianSchemes
{
default none;
laplacian(K,T) Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}

fluxRequired
{
default no;
T ;
}

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

(3) Why does it keep asking for a pressure initial condition for the porous media (solid) region? If it only solves a heat conduction equation, why is pressure field needed?

chao@ChaoCFDLinux:~/OpenFOAM/chao-2.3.0/run/oneChannePorousMediaHT$ chtMultiRegionSimpleFoam
/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.3.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 2.3.0-f5222ca19ce6
Exec : chtMultiRegionSimpleFoam
Date : Jul 24 2014
Time : 09:52:16
Host : "ChaoCFDLinux"
PID : 13319
Case : /home/chao/OpenFOAM/chao-2.3.0/run/oneChannePorousMediaHT
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

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

Create fluid mesh for region domainFluid for time = 0

Create solid mesh for region exRegionSolid for time = 0

*** Reading fluid mesh thermophysical properties for region domainFluid

Adding to thermoFluid

Selecting thermodynamics package
{
type heRhoThermo;
mixture pureMixture;
transport const;
thermo hConst;
equationOfState rhoConst;
specie specie;
energy sensibleEnthalpy;
}

Adding to rhoFluid

Adding to UFluid

Adding to phiFluid

Adding to gFluid

Adding to turbulence

Selecting turbulence model type laminar
Adding to ghFluid

Adding to ghfFluid

Selecting radiationModel none
Adding fvOptions

Creating finite volume options from fvOptions

Selecting finite volume options model type constantHeatTransfer
Source: fluidTosolid
- applying source for all time
- selecting inter region mapping
Creating mesh-to-mesh addressing for domainFluid and exRegionSolid regions using cellVolumeWeight
Overlap volume: 1.10097e-05
Selecting finite volume options model type interRegionExplicitPorositySource
Source: porosityBlockage
- applying source for all time
- selecting inter region mapping
Creating mesh-to-mesh addressing for domainFluid and exRegionSolid regions using cellVolumeWeight
Overlap volume: 1.10097e-05
*** Reading solid mesh thermophysical properties for region exRegionSolid

Adding to thermos

Selecting thermodynamics package
{
type heSolidThermo;
mixture pureMixture;
transport constIso;
thermo hConst;
equationOfState rhoConst;
specie specie;
energy sensibleEnthalpy;
}



--> FOAM FATAL IO ERROR:
cannot find file

file: /home/chao/OpenFOAM/chao-2.3.0/run/oneChannePorousMediaHT/0/exRegionSolid/p at line 0.

From function regIOobject::readStream()
in file db/regIOobject/regIOobjectRead.C at line 73.

FOAM exiting

(4) It appears the fvOptions has to be defined respectively for both regions, the fluid and the porous region (solid). Does it matter which one is the master region?

(5) Anyone has solved similar problems? And other suggestions to solve the problem?

Thank you so much!

[Adri_12]

Hi, titanchao

Did you have any answers to your problems ?

Thanks for your help !

Adrià

[Utkan]

I'm curious about the exact same problem, how to couple the porous region to air in this case? Anyone?

[choist31]

The key thing is porous media should be defined as fluid since it calculates the momentum(Pressure) sink. Thus, porous media can't be defined in solid region method even though code does not show any error or warning message (When you try to see the heat transfer and velocity in solid porous region, no effect is found). Please refer to chtMultiRegionSimple foam tutorial case; heat exchanger. I've make a lot of effort to add the porous features for 2DSolidQuenching tutorial case.

[mishrashubham]

Did any body solve above problem. How to use metal foam as a porous media?