[mohammad_kordo]

Hi to all In momentum equation effect of porous with considering volume averaged equation, is a source term named Darcy-Forchheimer term. It is considered as source term that added to momentum in UEqn.H file that can be seen in porousSimpleFoam or rhoPorousSimpleFoam solvers. But in energy equation, porous modeling is based on tow model. One is local thermal equilibrium and another non-thermal equilibrium. In local thermal equilibrium the temperature of solid (porous) and fluid is same and effect of porous properties (density, specific heat coefficient and thermal conductivity) is considered in fluid energy equation. Term of “rhof*cpf” (multiply of density in specific heat coefficient of fluid) in energy equation is modified to
rhof*cpf+rhos*cps*(1-epsilon)/epsilon : f:fluid, s:solid.
Also conductivity (k) is modified from kf to kf+ks*(1-epsilon)/epsilon.
In rhoPorousSimpleFoam solver and in EEqn.H file, these effects don’t exist. EEqn.H or energy equation for this solver is same to other solvers that don’t consider porous media (like rhoSimpleFoam). My question is about that.
How I can change the condition to that one? How I can consider the effect of porous properties in energy equation? How I can say to OepnFoam that in porous zone, conductivity and rho*cp is modified?

[bibin.sme]

Hi

Could you find some solution to the above problem?
please if so please give me some idea...

Regards
Bibin

[Adri_12]

Hi,

I am already wondering if that is not more interesting to start from chtMultiRegionFoam solvers implementing a porousity model in fvoption and applying it only in the porous domain.

Any ideas about this issue ?

adrià

[anuragm]

Originally Posted by Adri_12

Hi,

I am already wondering if that is not more interesting to start from chtMultiRegionFoam solvers implementing a porousity model in fvoption and applying it only in the porous domain.

Any ideas about this issue ?

adrià

But why start with chtMultiRegionFoam if there is only a need for porosity through fvOptions? The porosity can be defined only within a certain cellZone, for example.

[Adri_12]

I want to modelize heat transfers between air and porous zone considering two thermal equations (1 for the air and 1 for the solid porous zone), like mentionned in the post of mohammad amin.

Originally Posted by mohammad_kordo

Hi to all In momentum equation effect of porous with considering volume averaged equation, is a source term named Darcy-Forchheimer term. It is considered as source term that added to momentum in UEqn.H file that can be seen in porousSimpleFoam or rhoPorousSimpleFoam solvers. But in energy equation, porous modeling is based on tow model. One is local thermal equilibrium and another non-thermal equilibrium. In local thermal equilibrium the temperature of solid (porous) and fluid is same and effect of porous properties (density, specific heat coefficient and thermal conductivity) is considered in fluid energy equation. Term of “rhof*cpf” (multiply of density in specific heat coefficient of fluid) in energy equation is modified to
rhof*cpf+rhos*cps*(1-epsilon)/epsilon : f:fluid, s:solid.
Also conductivity (k) is modified from kf to kf+ks*(1-epsilon)/epsilon.
In rhoPorousSimpleFoam solver and in EEqn.H file, these effects don’t exist. EEqn.H or energy equation for this solver is same to other solvers that don’t consider porous media (like rhoSimpleFoam). My question is about that.
How I can change the condition to that one? How I can consider the effect of porous properties in energy equation? How I can say to OepnFoam that in porous zone, conductivity and rho*cp is modified?

that is why I mentionned the possibility to start with chtMultiRegionFoam. But I am wondering if the fvOptions defining a porous zone would be enough to consider the heat transfer + the Darcy behaviour of the fluid.

I hope it is more clear ?

Thanks for your help !

Adrià

[anuragm]

Originally Posted by Adri_12

that is why I mentionned the possibility to start with chtMultiRegionFoam. But I am wondering if the fvOptions defining a porous zone would be enough to consider the heat transfer + the Darcy behaviour of the fluid.

Starting with the basics:

1. The porous medium effects the momentum and temperature profiles in the flow
2. If you have a perfect description of the porous medium in your geometry, you do not need Darcy or any other modifications
3. However, in many cases porous media are non-uniform or just not worth the effort to describe accurately with all the details
4. So it makes sense to approximate their effect indirectly, by modifying the momentum and temperature equations
5. This modification can be achieved by either
   a. directly editing the UEqns.H and EEqns.H or equivalent files (requires writing equations & recompiling the solver)
   b. through the use of fvOptions (if solver includes support for it, then no recompilation needed)
6. In case of 5b. you will still need to look at the way the equations are implemented in the solver to add a source term that is consistent with the rest of the equation. You will need source terms for both energy and momentum in this case.

I am working with porous mediums as well, but I have only implemented an additional momentum source using the fvOptions at the moment. I will add the term for the energy equation in the near future. If you want to do it as well, the following resource will help.

https://web.stanford.edu/~csoulain/O...G_PART_3v5.pdf

[Adri_12]

Originally Posted by anuragm

1. The porous medium effects the momentum and temperature profiles in the flow
2. This modification can be achieved by either
   a. directly editing the UEqns.H and EEqns.H or equivalent files (requires writing equations & recompiling the solver)
   b. through the use of fvOptions (if solver includes support for it, then no recompilation needed)
3. In case of 5b. you will still need to look at the way the equations are implemented in the solver to add a source term that is consistent with the rest of the equation. You will need source terms for both energy and momentum in this case.

Thanks for your time and you answer and sorry for my late response. Your comments match with both possibilities I will try. I will give you more details when I get more results.

Adrià

[CriCri]

Hello,
Did you find a solution to the above problem? I'm working on a similar case using the ChTmultiRegion solver but I'm not sure how to implement an additional source term on the energy equation (as far as I understood the darcy forcheimer source term acts only on the momentum equation)
thanks for your help!

[wanghongjie]

Originally Posted by anuragm

Starting with the basics:

1. The porous medium effects the momentum and temperature profiles in the flow
2. If you have a perfect description of the porous medium in your geometry, you do not need Darcy or any other modifications
3. However, in many cases porous media are non-uniform or just not worth the effort to describe accurately with all the details
4. So it makes sense to approximate their effect indirectly, by modifying the momentum and temperature equations
5. This modification can be achieved by either
   a. directly editing the UEqns.H and EEqns.H or equivalent files (requires writing equations & recompiling the solver)
   b. through the use of fvOptions (if solver includes support for it, then no recompilation needed)
6. In case of 5b. you will still need to look at the way the equations are implemented in the solver to add a source term that is consistent with the rest of the equation. You will need source terms for both energy and momentum in this case.

I am working with porous mediums as well, but I have only implemented an additional momentum source using the fvOptions at the moment. I will add the term for the energy equation in the near future. If you want to do it as well, the following resource will help.

https://web.stanford.edu/~csoulain/O...G_PART_3v5.pdf

Did you have add the energy equation to the porous..Foam? I have a similar question, and I only have a solution to compile cht-like Foam which includes fluid and solid. Maybe you have a better solution, help me, please.

[Utkan]

Originally Posted by anuragm

Starting with the basics:

1. The porous medium effects the momentum and temperature profiles in the flow
2. If you have a perfect description of the porous medium in your geometry, you do not need Darcy or any other modifications
3. However, in many cases porous media are non-uniform or just not worth the effort to describe accurately with all the details
4. So it makes sense to approximate their effect indirectly, by modifying the momentum and temperature equations
5. This modification can be achieved by either
   a. directly editing the UEqns.H and EEqns.H or equivalent files (requires writing equations & recompiling the solver)
   b. through the use of fvOptions (if solver includes support for it, then no recompilation needed)
6. In case of 5b. you will still need to look at the way the equations are implemented in the solver to add a source term that is consistent with the rest of the equation. You will need source terms for both energy and momentum in this case.

I am working with porous mediums as well, but I have only implemented an additional momentum source using the fvOptions at the moment. I will add the term for the energy equation in the near future. If you want to do it as well, the following resource will help.

https://web.stanford.edu/~csoulain/O...G_PART_3v5.pdf

I am also curious whether you were able to find a way to implement the energy equation.