CFD Online Discussion Forums - Interface boundary condition

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Hi Max,

If there is a fluid on one side and solid on the other side, then a wall at the interface should be given coupled wall condition to balance the transfer at the surface.

If it is a wall, between two fluids, for the flow to happen, the interface should be 'interior'.
For heat transfer, what should be the condition at the interface?

Hi,
If there is a fluid on one side and solid on the other side, then a wall at the interface should be given coupled wall condition to balance the transfer at the surface.

If it is a wall, between two fluids, for the flow to happen, the interface should be 'interior'.
For heat transfer, what should be the condition at the interface?

Quote:

Originally Posted by myworkcfd (Post 652097)

If there is a fluid on one side and solid on the other side, then a wall at the interface should be given coupled wall condition to balance the transfer at the surface.

If "balance the transfer" means "allow heat transfer", then yes.

Quote:

If it is a wall, between two fluids, for the flow to happen, the interface should be 'interior'.

No, it should then be 'interface', not 'interior'. These are two different words, and not the same.

Quote:

For heat transfer, what should be the condition at the interface?

The type of boundary condition depends on if you are connecting solid to liquid or liquid to liquid. See sketch below:

Code:

+---------------+

|     SOLID     |

+--shadow-wall--+

+------wall-----+

|     LIQUID    |

+---------------+



+---------------+

|     LIQUID    |

+---interface---+

+---interface---+

|     LIQUID    |

+---------------+

For Fluent, a porous medium is a special kind of liquid. You don't have to do anything special to 'turn on' heat transfer over the interface.

free surface radiation simulation in an enclosure in FLUENT

Hello,
I would like to calculate the radiation from the liquid metal surface to the surrounding walls and the lid, in a half filled ladle in FLUENT. I am using the multiphase VOF model with liquid metal half filled in the ladle and hot air above it.

If anyone had an experience in simulating such a problem, kindly help me.

Thank you Pakk.

I have modeled flow through porous medium with adjacent fluid media in GAMBIT. If the edge in between porous medium region and fluid region is given as interface in GAMBIT, there is nothing left for mesh interface in FLUENT.If I try to initialize the flow in FLUENT, error is displayed regarding these interfaces.

So,I gave these edges as interior.I could then see a converged solution.

Is giving interior correct?

I don't know about Gambit, maybe Gambit uses different terms.

But I know that as soon as you are in Fluent, you should see "interface" at those places. If you see "interior", you are talking about something else.

Quote:

Originally Posted by engahmed (Post 260179)

Thank you max. I now know I don't need to define any interfaces in my domain.....May I please ask you another question? I know how to define a porous medium and everything, what is confusing me is the "line" separating the fluid and the porous medium, how to define it? imagine, it is a 2D case with water layer and a porous medium layer, so the line separating them, do I define it as an interior or what to model heat transfer between the two layers??
thanks a lot

hello engahmed, have u solved the issue..? im having the same issue as urs. once porous domain is created, additional interface is created for solid zone. i dont know how this should be considered in boundary condition.