[Hexahedron]

I have the following problem for which I have found no solution so far.

I have a porous media zone surrounded by solid regions. There is a heat source on one side of the solid regions and so heat is conducted through the solid to the interface between the solid region and the porous media.

Now as I'm using the non-equilibrium thermal model in the porous zone, there are separate energy equations for the fluid and solid in the porous medium, which are coupled together through convective heat transfer. Also, Fluent creates a wall and its shadow interface between the solid region and the porous fluid for which heat transfer is coupled.

As There is a separate energy equation for the porous solid, a third interface is also created between the porous solid and the solid region. However options for this interface are the same as for boundary walls, meaning that by default heat flux is set to zero so that there is no direct heat transfer between the solid region and the porous solid. There is also no obvious way to couple the porous solid with the solid region at the interface.

Now since I have temperatures of over 1000 degrees Celsius, heat transfer from the solid region to the porous solid due to radiation would be significant. Currently, with only the porous fluid energy equation coupled with the solid region the results are poor as the heat transfer from solid to porous solid is not accounted for. As such, the non-equilibrium thermal model seems pretty useless to me.

Has anyone come across the same problem or have idea of how to properly couple heat transfer at the solid and porous solid interface, possibly with UDFs?

[talkas]

Hello,

Do you have a solution for this problem? I tried to couple solid wall with porous solid by using TUI, but I could not solve the problem.

Thanks in advance.

[Hexahedron]

No solution to this problem yet. I have tried a couple of approaches with UDFs but they don't work quite as expected. I have tried with setting corresponding energy source and sink terms in solid cells that are next to walls for both sides of the wall (solid and porous solid), but this is problematic.

To make it really work might require more detailed information about how Fluent handles conjugate heat transfer in this kind of boundary and maybe even modifications to source code.

[talkas]

Hello again,
I found a way to achieve heat transfer between two porous region. Firstly, two adjacent fluid walls need to be coupled by defining interface boundary condition. Then other created solid walls ,such as wall:0XX, need to be coupled again selecting coupled walls options in creating interface menu. At last you have two interface at the same adjacent location. Besides, these steps can be done by defining only one interface with 4 adjacent walls. In this case heat transfer rate does not the same as in the case of 2 interface. The results are not even close to each other. I could not find the problem.

[vinayakvkp]

Dear Mr. Talkas could you please elaborate further?

[Manasilavhekar]

Originally Posted by Hexahedron

I have the following problem for which I have found no solution so far.

I have a porous media zone surrounded by solid regions. There is a heat source on one side of the solid regions and so heat is conducted through the solid to the interface between the solid region and the porous media.

Now as I'm using the non-equilibrium thermal model in the porous zone, there are separate energy equations for the fluid and solid in the porous medium, which are coupled together through convective heat transfer. Also, Fluent creates a wall and its shadow interface between the solid region and the porous fluid for which heat transfer is coupled.

As There is a separate energy equation for the porous solid, a third interface is also created between the porous solid and the solid region. However options for this interface are the same as for boundary walls, meaning that by default heat flux is set to zero so that there is no direct heat transfer between the solid region and the porous solid. There is also no obvious way to couple the porous solid with the solid region at the interface.

Now since I have temperatures of over 1000 degrees Celsius, heat transfer from the solid region to the porous solid due to radiation would be significant. Currently, with only the porous fluid energy equation coupled with the solid region the results are poor as the heat transfer from solid to porous solid is not accounted for. As such, the non-equilibrium thermal model seems pretty useless to me.

Has anyone come across the same problem or have idea of how to properly couple heat transfer at the solid and porous solid interface, possibly with UDFs?

Have you found a solution to this problem?

[pghoseju]

Originally Posted by talkas

Hello again,
I found a way to achieve heat transfer between two porous region. Firstly, two adjacent fluid walls need to be coupled by defining interface boundary condition. Then other created solid walls ,such as wall:0XX, need to be coupled again selecting coupled walls options in creating interface menu. At last you have two interface at the same adjacent location. Besides, these steps can be done by defining only one interface with 4 adjacent walls. In this case heat transfer rate does not the same as in the case of 2 interface. The results are not even close to each other. I could not find the problem.

Two overlapped interfaces will be first coupled. Then second, which iremai ing nterfaces should be coupled using coupled option???

[Hasan_Najafi]

Hi guys,

I'am in the same issue. When you generated the solid zone, what did you do with the boundary of your solid zone. In my case, I have rectangular fluid and solid (porous) zone in the center and all four edge of them covered by solid zones. There is interface boundary between fluid zone in the center and solid zone around it. But, when the solid zone of porous is created by fluent, it has own boundaries. So, what boundary type should I chose for them?

Is there anybody here that found solution for it?

Thanks

[ubadekemerli]

Hello everyone,

I have found a solution. It's kinda weird, but you need to have non-overlapping mesh at the interface first. Then the program will create some interfaces. Delete all of them. Then turn the porous media non-equilibrium on. You will have the new zones and faces like "heater_region:040". The faces having ":" and a number at the end are for the porous solid regions. Convert those zones from "wall" to "interface". Then go to mesh interface and manually create a new interface. There you can have multiple selections. Just make sure you have added three of the zones (one for solid face, one for fluid, and one for porous solid).

[sajjan]

Originally Posted by ubadekemerli

Hello everyone,

I have found a solution. It's kinda weird, but you need to have non-overlapping mesh at the interface first. Then the program will create some interfaces. Delete all of them. Then turn the porous media non-equilibrium on. You will have the new zones and faces like "heater_region:040". The faces having ":" and a number at the end are for the porous solid regions. Convert those zones from "wall" to "interface". Then go to mesh interface and manually create a new interface. There you can have multiple selections. Just make sure you have added three of the zones (one for solid face, one for fluid, and one for porous solid).

I am facing the same issue. Can you please elaborate what do you mean by "need to have non-overlaping mesh at the interface?".
for me, there is no option to chose the connecting walls as interface option. I have only five different options to choose from: fan, interior, porous jump, wall, and radiator. Basically, I donot see an option to change two coupled walls to interface.