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 tH3f0rC3 March 21, 2011 03:43

heat transfer with OpenFoam

Dear all,

I want to model a turbulent flow with heat transfer caused by forced convection and radiation.
How can I model that with OF. I have checked the tutorial files of the heat transfer solvers. I every solver-file there are the following files: alphatwallfunction, epsilon, k, nut, p, p_rgh, T, T.org, U.
- What is the meaning of them (T=temperature, U=velocity.)?
- Is it possible to enter a heat transfer coefficient calculated by my own or does OF calculate everything by itself?

Best Regards,
tH3f0rC3

 ang_dipl_ing_fd March 21, 2011 17:54

hi,
-alphatWallFunction=turbulent thermal diffusity (or eddy thermal diffusity)
-k=turbulent energy
-epsilon=dissipation
-nut=turbulent viscosity
-p=pressure, exact: pressure/rho for inkompressible Solver
-p_rgh=hydrostatic pressure p_0+rho*g*h (same as above p_0/rho+g*h); if g=(0 0 0) than p=p_rgh
-T=temperature [K]
-T.org=backup for T
-U=velocity (vector)
and the last, which you forget
-kappat=turbulent thermal conductivity

i think you define the heat transfer coefficient over the Pr in transportProperties. but i'm not sure.

 tH3f0rC3 March 22, 2011 03:03

I have now checked the buoyantSimpleRadiationFoam-solver. There are some more files.
Do you know the meaning of them, too?

G
mut

Regards,
tH3f0rC3

 tH3f0rC3 March 22, 2011 03:48

I have tried to use the buoyantSimpleRadiationFoam-solver for an easy model.
The folliwing error appears:

Create time
Create mesh for time = 0

Selecting thermodynamics package hPsiThermo<pureMixture<constTransport<specieThe rmo<hConstThermo<perfectGas>>>>>
#0 Foam::error::printStack(Foam::Ostream&) in "/data/caehgb.za/studienarbeit-di rk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libOpenFOA M.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/data/caehgb.za/studienarbeit-dirk/work /OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 __restore_rt in "/lib64/tls/libc.so.6"
#3 Foam::hPsiThermo<Foam::pureMixture<Foam::constTran sport<Foam::specieThermo<F oam::hConstThermo<Foam::perfectGas> > > > >::calculate() in "/data/caehgb.za/stu dienarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPO pt/libbasicThermophysicalModels.so"
#4 Foam::hPsiThermo<Foam::pureMixture<Foam::constTran sport<Foam::specieThermo<F oam::hConstThermo<Foam::perfectGas> > > > >::hPsiThermo(Foam::fvMesh const&) in "/data/caehgb.za/studienarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7 .1/lib/linux64GccDPOpt/libbasicThermophysicalModels.so"
#5 Foam::basicPsiThermo::addfvMeshConstructorToTable< Foam::hPsiThermo<Foam::pur eMixture<Foam::constTransport<Foam::specieThermo<F oam::hConstThermo<Foam::perfec tGas> > > > > >::New(Foam::fvMesh const&) in "/data/caehgb.za/studienarbeit-dirk /work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libbasicTher mophysicalModels.so"
#6 Foam::basicPsiThermo::New(Foam::fvMesh const&) in "/data/caehgb.za/studienar beit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/lib basicThermophysicalModels.so"
#8 __libc_start_main in "/lib64/tls/libc.so.6"
#9 Foam::regIOobject::writeObject(Foam::IOstream::str eamFormat, Foam::IOstream: :versionNumber, Foam::IOstream::compressionType) const in "/data/caehgb.za/studi enarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/applications/bin/li nux64GccDPOpt/buoyantSimpleRadiationFoam"
Floating point exception

Can someone help me?
Maybe OF isn't installed correct?

Regards

 tH3f0rC3 March 22, 2011 03:53

Quote:
 Originally Posted by ang_dipl_ing_fd (Post 300423) hi, may be this will help you: -alphatWallFunction=turbulent thermal diffusity (or eddy thermal diffusity) -k=turbulent energy -epsilon=dissipation -nut=turbulent viscosity -p=pressure, exact: pressure/rho for inkompressible Solver -p_rgh=hydrostatic pressure p_0+rho*g*h (same as above p_0/rho+g*h); if g=(0 0 0) than p=p_rgh -T=temperature [K] -T.org=backup for T -U=velocity (vector) and the last, which you forget -kappat=turbulent thermal conductivity i think you define the heat transfer coefficient over the Pr in transportProperties. but i'm not sure.
Hi ang_dipl_ing_fd,

do you also know the following:
In the thermophysical properties:
mixture air 1 28.9 1000 0 1.8e-05 0.7;

What does that mean?
Does every number have a meaning?

Best Regards

 alvora March 22, 2011 04:38

Hi

In the thermophysical properties:
mixture air 1 28.9 1000 0 1.8e-05 0.7;

The thermalPhsical Properties is calculated based which model you specified, like
if model is hPsiThermo, calculation based on enthalpy 'h' and compressibility 'psi'.
and if model is hRhoThermo, calculation based on enthalpy or sensible enthalpy.
and if model is pureMixture, calculation based on passive gas mixtures.

parameters :

air is mixture fluid name
1 is for pure Mixture (mixture property) (number of molecules of species)
28.9 for molecule weight (kg/kmol)
1000 for heat capacity at constant pressure [J/kmol K]
0 for reference enthalpy [J/kmol]
1.8e-05 for Dynamics viscosity (kg/ms)
0.7 is for Prandtl number.

you can change properties according to your problem (fluid).

best luck

Alpesh

 sixwp March 22, 2011 04:58

Quote:
 Originally Posted by tH3f0rC3 (Post 300472) Hi ang_dipl_ing_fd, do you also know the following: In the thermophysical properties: mixture air 1 28.9 1000 0 1.8e-05 0.7; What does that mean? Does every number have a meaning? Best Regards
Hi tH3f0rc3 (hard to say :-p)

As far as I know:

1 => Number of moles of this specie
28,9 => Molecular weight
1000 => Cp (Specific heat capacity)
0 => heat of fusion (useless, I guess in your case)
1.8e-05 => dynamic viscosity
0.7 => Prantl number

Quote:
 Originally Posted by tH3f0rC3 (Post 300472) Reading g Reading thermophysical properties Selecting thermodynamics package hPsiThermo>>>> #0 Foam::error::printStack(Foam::Ostream&) in "/data/caehgb.za/studienarbeit-di rk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libOpenFOA M.so" #1 Foam::sigFpe::sigFpeHandler(int) in "/data/caehgb.za/studienarbeit-dirk/work /OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libOpenFOAM.so" #2 __restore_rt in "/lib64/tls/libc.so.6" #3 Foam::hPsiThermo > > > >::calculate() in "/data/caehgb.za/stu dienarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPO pt/libbasicThermophysicalModels.so" #4 Foam::hPsiThermo > > > >::hPsiThermo(Foam::fvMesh const&) in "/data/caehgb.za/studienarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7 .1/lib/linux64GccDPOpt/libbasicThermophysicalModels.so" #5 Foam::basicPsiThermo::addfvMeshConstructorToTable< Foam::hPsiThermo > > > > >::New(Foam::fvMesh const&) in "/data/caehgb.za/studienarbeit-dirk /work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libbasicTher mophysicalModels.so" #6 Foam::basicPsiThermo::New(Foam::fvMesh const&) in "/data/caehgb.za/studienar beit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/lib basicThermophysicalModels.so" #7 main in "/data/caehgb.za/studienarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/ OpenFOAM-1.7.1/applications/bin/linux64GccDPOpt/buoyantSimpleRadiationFoam" #8 __libc_start_main in "/lib64/tls/libc.so.6" #9 Foam::regIOobject::writeObject(Foam::IOstream::str eamFormat, Foam::IOstream: :versionNumber, Foam::IOstream::compressionType) const in "/data/caehgb.za/studi enarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/applications/bin/li nux64GccDPOpt/buoyantSimpleRadiationFoam" Floating point exception
I'm also interested in this matter (I've got the same issue but with chtMultiRegionSimpleFoam). Someone clever than us? ^^

Cheers guys :)

: I was too slow, apparently (damn coffee break ! :-D), sorry for this double answer

 tH3f0rC3 March 22, 2011 05:26

Hey,
Do you also know, where I can type in the properties of the walls, for example that a wall consists of nickel?

Regards,
tH3f0rC3

 sixwp March 22, 2011 06:28

It depends what you want to do:

for a fixed temperature wall, you don't need to input any properties. (only create a radiationProperties file => check the tutorial hotRadiationRoom). In 0/T, fixe the wall temperature.

If you're really eager to use the wall properties, include it in the mesh and use a MultiRegion solver (much more complicated, for my level of knowledge obviously).

cheers

 tH3f0rC3 March 22, 2011 06:44

OK, but I think i have to gibe the solver an information of the material which should be heaten up. For example the density or cp...
Where can I do that?

Best Regards,
tH3f0rC3

 sixwp March 22, 2011 06:47

I think I got your case wrong:
Can you explain briefly what your heat transfer consist in? And add your directories files also, if you don't mind.

 tH3f0rC3 March 22, 2011 06:58

I want to simulate a heat transfer from a turbulent (I guess so) flow to a surface, that should be heaten up.
In addition to that there is also radiation from the hot wall to the surface.

If this description is too short, please let me know.

Which files do you want to see?

Regards,
tH3f0rC3

 tH3f0rC3 March 22, 2011 07:18

Quote:
 Originally Posted by sixwp (Post 300480) Hi tH3f0rc3 (hard to say :-p) I'm also interested in this matter (I've got the same issue but with chtMultiRegionSimpleFoam). Someone clever than us? ^^
Hi sixwp,

it is exactly the same issue just with other file dorectory?

Regards

 sixwp March 22, 2011 09:38

Quote:
 Originally Posted by tH3f0rC3 (Post 300497) I want to simulate a heat transfer from a turbulent (I guess so) flow to a surface, that should be heaten up. In addition to that there is also radiation from the hot wall to the surface. If this description is too short, please let me know. Which files do you want to see? Regards, tH3f0rC3
I'm sorry, I must be tired, I don't really see what's your geometry's like. Can you show me a raw scheme?

Concerning the directories files: can you post your 0, constant and system folders? Maybe (not likely but, who knows), I'll be able to find out your problem and therefore, mine :-)

 tH3f0rC3 March 22, 2011 09:42

Yes, of course.
But you have to give me an email adress of yours, because I can't post fotos.

Regards

 tH3f0rC3 March 23, 2011 06:57

Hi,

is there someone else, who understands the following error message?

Create time
Create mesh for time = 0

Selecting thermodynamics package hPsiThermo<pureMixture<constTransport<specieThe rmo<hConstThermo<perfectGas>>>>>
#0 Foam::error::printStack(Foam::Ostream&) in "/data/caehgb.za/studienarbeit-di rk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libOpenFOA M.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/data/caehgb.za/studienarbeit-dirk/work /OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 __restore_rt in "/lib64/tls/libc.so.6"
#3 Foam::hPsiThermo<Foam::pureMixture<Foam::constTran sport<Foam::specieThermo<F oam::hConstThermo<Foam::perfectGas> > > > >::calculate() in "/data/caehgb.za/stu dienarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPO pt/libbasicThermophysicalModels.so"
#4 Foam::hPsiThermo<Foam::pureMixture<Foam::constTran sport<Foam::specieThermo<F oam::hConstThermo<Foam::perfectGas> > > > >::hPsiThermo(Foam::fvMesh const&) in "/data/caehgb.za/studienarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7 .1/lib/linux64GccDPOpt/libbasicThermophysicalModels.so"
#5 Foam::basicPsiThermo::addfvMeshConstructorToTable< Foam::hPsiThermo<Foam::pur eMixture<Foam::constTransport<Foam::specieThermo<F oam::hConstThermo<Foam::perfec tGas> > > > > >::New(Foam::fvMesh const&) in "/data/caehgb.za/studienarbeit-dirk /work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/libbasicTher mophysicalModels.so"
#6 Foam::basicPsiThermo::New(Foam::fvMesh const&) in "/data/caehgb.za/studienar beit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/lib/linux64GccDPOpt/lib basicThermophysicalModels.so"
#8 __libc_start_main in "/lib64/tls/libc.so.6"
#9 Foam::regIOobject::writeObject(Foam::IOstream::str eamFormat, Foam::IOstream: :versionNumber, Foam::IOstream::compressionType) const in "/data/caehgb.za/studi enarbeit-dirk/work/OpenFoam_ParaView/OpenFOAM/OpenFOAM-1.7.1/applications/bin/li nux64GccDPOpt/buoyantSimpleRadiationFoam"
Floating point exception

 tH3f0rC3 March 23, 2011 08:40

I know now, that this error message appears every time I want to involve the heat transfer.
Maybe this helps.

 ang_dipl_ing_fd March 27, 2011 15:57

hi tH3f0rC3,
did you run the tutorials without any change?

 val46 March 29, 2011 02:46

Quote:
 Originally Posted by tH3f0rC3 (Post 300493) OK, but I think i have to gibe the solver an information of the material which should be heaten up. For example the density or cp... Where can I do that? Best Regards, tH3f0rC3
Hi,

if I get you right you just have one fluid domain.
If you want to know the interaction of the fluid with a connected solid than you need a multiregion solver.
(density and cp are values connected to a volume and not to a surface)

Regards,
Toni

 tH3f0rC3 March 30, 2011 02:24

Hello,

I have another question to
-k=turbulent energy
-epsilon=dissipation
-nut=turbulent viscosity

I have to set up these files in the 0-file as boundary cinditions.
k and epsilon must have a value for the inlet surfaces. But how can I calculate these values?
And what is meant with the values

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