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-   -   [GAMBIT] Connection faces-volume (http://www.cfd-online.com/Forums/ansys-meshing/117258-connection-faces-volume.html)

kalene86 May 5, 2013 15:42

Connection faces-volume
 
1 Attachment(s)
Hi everybody!
I am an engineering student and Iím preparing my masterís degree thesis. I am studying Thermal Energy Storage Systems. In particular Iím focusing on air motion inside a cylinder of porous material. I designed the fluid cell in Gambit ( I have never used this programme before) whose dimensions are 1mmx1mmx500m. In order to get accurate results I inserted 50 sections throughout the volume of the fluid cell.
Can you please tell me how to match each of these faces to the volume?
:confused:

-mAx- May 6, 2013 02:50

try connect faces
But what is exactly the purpose for inserting those sections?
(if you want later having post-data on those sections), you are not enforce to create them in your mesh.
I would create your parallepiped with 1*1*500 (no unit in Gambit, but scale in Fluent), and you can mesh it on the fly.

kalene86 May 6, 2013 04:44

Hi max!
The teacher told me to put these inner sections, so that, in fluent I may know the temperature on them!

-mAx- May 6, 2013 04:57

ok, but then you will need to define them as internal (or interior I don't remember) in the BC Panel (else gambit will fuse those sections with the fluid domain)
Again you can also do that later in Fluent with Post-process.
If you want to monitor temperature at each sections DURING the iterations, you can monitor some points.
But anyway if you want to have those sections, you have to connect faces between your volumes.
http://aerojet.engr.ucdavis.edu/gamb...m_face_connect
in the pull down panel "select", choose All
It should connect all the surfaces
The surfaces should appear in pink if "connectivity color based" mode is enabled
http://aerojet.engr.ucdavis.edu/gamb...m#gc_speccolor

kalene86 May 6, 2013 04:58

I'm trying to connect the faces, but the following error:

the call to connect on list on faces resulted in no actual connect operations...

:(

-mAx- May 6, 2013 06:22

try with "real & virtual"

kalene86 May 8, 2013 06:35

error in fluent
 
Hello max!!Thanks for your advice.
I solved my problem this way:
I made a face, mesh, extrude with mesh (50 times).
In the boundary conditions i have defined the inner sections as interior.

Now, when I import the file into fluent, after the iteration displays the following error message:

iter continuity x-velocity y-velocity z-velocity energy time/iter

reversed flow in 100 faces on outflow 5.

Error: Floating point error: invalid number

Error Object: ()

Error: Floating point error: invalid number

Error Object: ()

Error: Floating point error: invalid number

Error Object: ()

Error: Floating point error: invalid number

Error Object: ()

Error: Floating point error: invalid number

Error Object: ()
1 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 0:06:06 2

reversed flow in 100 faces on outflow 5.
2 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 0:03:08 1

reversed flow in 100 faces on outflow 5.
3 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 1.#QNBe+00 0:00:00 0


thanks a lot for your answers!!:confused:

-mAx- May 8, 2013 06:58

Hello,
Are your faces all connected? As I said your can check it: the surfaces should appear in pink if "connectivity color based" mode is enabled

Else in Fluent what are the BC listed?

kalene86 May 8, 2013 10:32

1 Attachment(s)
Connectivity based color: the color of the faces is MAGENTA!! (Photo)

The boundary conditions are:
input: velocity inlet
output: outflow
exterior walls: wall
internal section: interior

-mAx- May 8, 2013 12:36

ok, then try internal instead of interior
If it is not ok, try to merge all your volumes for having no interior.
If is still not ok, then it lies on your BC (you can give your value), but I wouldn't use outflow for outlet. Use pressure-outlet.
EDIT: what gives you a check mesh in fluent?

Far May 8, 2013 12:46

-mAx-: Your original idea of making planes, in post processing program where data to be measured, was perfect idea.

Only one need to measure location in gambit to put the location coordinates in post processing software.

kalene86 May 30, 2013 19:20

Sorry!
 
Hello Max, I'm sorry if I have not replied more, but I had some problems with the thesis. Unfortunately, the assistant who was following my work is gone and I'm in serious difficulty.

After you have modeled this cell fluid, and after importing ii into fluent, my professor said I should get the "heat transfer coefficient" (h) with and without radiation.

I have no idea of how to do, and no one can tell me how to do it!

Sorry for my english!:(

-mAx- June 3, 2013 01:23

Open a new thread in the Fluent Forum (I am not familiar with radiation etc...).


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