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-   -   Interface boundary condition (https://www.cfd-online.com/Forums/fluent/76390-interface-boundary-condition.html)

pakk January 19, 2016 05:34

I am sorry but I don't understand what you are asking.

ksujeet213@ January 20, 2016 01:13

my question is....
i have two pipes .....i want to put a heat exchanger or valve btween them.
how it can be done?
and how can i put boundary conditions on it?
please reply me

ksujeet213@ January 27, 2016 03:32

my question is....
i have two pipes .....i want to put a heat exchanger or valve btween them.
how it can be done?
and how can i put boundary conditions on it?
please reply me

ksujeet213@ February 2, 2016 06:49

hii max ..
i have a problem....
In my project i have two pipes with same material.....i want to put a boundary condition in between two pipes (pressure drop. for heat exchanger) how can i do??

Nuha June 26, 2016 07:57

coupling of default interiors
 
Hi

i m working on a cylindrical 2D column of fluidized bed. upon separating it into two zones , two default interiors and one side wall is generated. after injecting particles by surface injection and running the simulation , i didn't get bed expansion.

So my question is that is there any need to couple the interiors o transfer information to next cells as in my view the default interior in between other two is not participating in calculations.

plz reply it soon as my project is just stucked due to this.

H_rez September 30, 2016 10:45

In modelling of mixer in fluent(using gambit as meshing software) should i use interior boundry condition or interface boundry condition between the moving fluid and stationary fluid in MRF model ?

-mAx- October 10, 2016 02:04

https://www.sharcnet.ca/Software/Flu...tg/node135.htm
check step 4

H_rez October 10, 2016 05:29

Thank you max
i have another question, recently in a youtube video i have seen that in a 3D simulation of a mixer he uses interface not interior as boundry between the fluid can you please tell me the difference? is using one or another wrong or does it depend on the persons point of view ?

-mAx- October 10, 2016 06:27

I was used to work with interface (and not interior), for moving mesh for instance.
I never used MRF Model

H_rez October 10, 2016 06:43

Thank again
If the mesh on the interfaces do not match in gambit is that a problem or does it get fixed when we use mesh interface in ansys fluent ? and how do we fix this problem if they do not match?

-mAx- October 10, 2016 06:51

That's the aim for interface.
You disconnect both meshes (stator/rotor), and by applying interface on each domain you will enforce the solver to interpolate values on interfaces, even if meshes don't match.

H_rez October 10, 2016 07:23

Thank you max you have been very helpful

Adarsh nair November 18, 2016 03:47

I have a problem i have to apply a heat flux in the interface of fluid and solid domain,but fluent solver is recognising the face default as interface ,so cannot apply heat flux ,plz sugust me a solution

pakk November 18, 2016 06:59

You probably did not tell Fluent yet that the solid part is really solid. Go to the cell zone menu, select the cell zone that should be solid, and change it from "fluid" into "solid".
The interface boundary should now change into a wall boundary (and a shadow-wall boundary should be added), and I then you can proceed in the boundary condition menu by adding a heat source on the boundary.

oozcan November 18, 2016 08:12

that is, if you do change ''shadow-wall'' to ''wall'' , two walls become ''only one'' wall. Then, you can apply temp. , heat flux. etc.

pakk November 18, 2016 08:47

I would not change one "shadow-wall" into a "wall". You can add heat fluxes without doing this. If you change "shadow-wall" into a "wall", then at best you do nothing, and at worst you confuse Fluent and will get strange errors later on.

oozcan November 18, 2016 09:57

It is not written to be calculated ''heat transfer''. That's why I have supposed a wall is needed to apply heat flux. If heat flux has been required in heat transfer surface, then, yes, I agree with that.That is, it is enough to define heat flux in '' wall'' instead of ''shadow-wall''. Because shadow-wall is generated by FLUENT.

myworkcfd June 6, 2017 09:54

Hi
Iam trying to simulate the heat transfer through porous medium.
Air enters and leaves the porous medium(porous medium-bottom wall is hot).

I have created the model in GAMBIT.I have taken a big domain, have split it in to 3 regions,named the middle region as porous , while left and right of porous are fluids.
If I specify the both the interfaces (left and right of porous medium)as wall in GAMBIT , 2 walls and corresponding wall shadows are formed in fluent. I have specified the fluid as air.Specified the porous medium parameters also.The case is not converging in FLUENT.

If I do not specify the interface in GAMBIT, the case converges.

Which method is correct?

oozcan June 6, 2017 10:39

could you explain it a little bit more by using some screenshots including the model you have made?

myworkcfd June 6, 2017 11:17

1 Attachment(s)
Thanks for the reply.

As shown in the model, 3 fluid zones were created in GAMBIT.
The edge joining left fluid and the centre fluid is given boco as wall1 and the edge joining right fluid and centre fluid is given the boco as wall2.

When exported to FLUENT, 2 shadow walls were created.Also, I have changed the middle fluid to porous with the corresponding inputs.

To simulate the flow through the porous medium, these two walls are to be changed to interior.

To simulate the heat transfer, after switching the energy equation on , should I keep these walls as interiors, or should I change to some other bocs for heat transfer.The bottom wall of the middle fluid has heat generation of 200w/m2.


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