CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

Porous media setup issues in Fluent

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   January 24, 2011, 19:25
Default Porous media setup issues in Fluent
  #1
New Member
 
B
Join Date: Jan 2011
Posts: 2
Rep Power: 0
Bernard Van is on a distinguished road
Hi everyone,

I am using ANSYS workbench 12.1, academic licence. I am trying to model a very simple problem in FLUENT but have issues setting it up as I am not familiar with workbench. I hope someone can help me.

Set up:
-model a pipe (rectangular shape) with a porous media piece inside. The flow is going in the pipe, going through the porous media and getting out at the outlet of the same pipe.

STEP 1:
Using Design Modeler, I tried 2 methods:
-sketch the cross section and extrude (2 sketches, 1 for the pipe without porous media, 1 for the pipe that has the porous media inside)
-build 3 boxes (1 for the inlet part, 1 for the media part, 1 for the outlet part)
In both cases, I use the function FREEZE so that the software does not fuse the pieces together as 1 big piece automatically, as the 3 pieces are in contact on the whole cross section area.
I set all the pieces to liquid.

STEP 2:
Using Meshing 12.1:
-I need to use a sweep method which I implemented successfully
-I use the function "Create Named Selection" to set up the inlet, outlet, and symmetry
Now, here is the beginning of all my issues.
-The software set contacts automatically, and I choose "No Separation - fluid to fluid" and I think that the contact between the porous media and the non porous media is where my problem is. I tried all the contact types that are available to me, but it is not working.

STEP 3:
Fluent:
-When exporting to Fluent, the interface between the porous media boundary and the non porous media (on the cross section) is considered as a wall, where I believe, it shouldn't.
-When I try to go back to STEP 2 and create the "Named Selection" of those interfaces to "interior", to force Fluent to consider those surfaces as interior and not walls, an error message appear when importing it on Fluent saying:
"Model information file is not compatible with mesh"
and a similar message on the workbench window.

I am confident setting up the porous media then on Fluent, but the issue I have is during the set up of the mesh/geometry model.
I am aware that my issue is concerning the interface, contact between my porous media and my fluid inlet and outlet medias.
How can I solve that issue ?
I tried to look around and couldn't find any details for solutions for this simple issue.

Maybe it has changed or I am not doing it the right way, but I believe that the porous media interface has to be set to interior and NOT wall or fluent will consider it as a barrier when it is a porous media where fluid can go through it.

I am looking for help and input using workbench 12.1 before I switch back to Gambit/Fluent old days.

Thank you very much everyone for your help,

Bernard,
Bernard Van is offline   Reply With Quote

Old   January 27, 2011, 01:11
Default
  #2
New Member
 
miftah
Join Date: Nov 2009
Posts: 3
Rep Power: 7
asubajingan is on a distinguished road
Have you try to set interface BC in your connection. Then create interface mesh in the interface side.
asubajingan is offline   Reply With Quote

Old   January 28, 2011, 14:31
Default
  #3
New Member
 
B
Join Date: Jan 2011
Posts: 2
Rep Power: 0
Bernard Van is on a distinguished road
I am not familiar with the new interface and using workbench.

Do I have to set the interface BC using the modeler (not too sure, the modeler seems pretty basic) or meshing ? In Meshing, I tried to set up some contact conditions but none of them worked.
Bernard Van is offline   Reply With Quote

Old   January 27, 2012, 00:19
Default
  #4
New Member
 
Sabrina
Join Date: Nov 2011
Posts: 11
Rep Power: 5
Sabrinache is on a distinguished road
Hello Bernard,

I have read your thread, and found out I am facing same problem.

I have a rectangular section in which there is a porous media. I have prepared the rectangular section, made a surface as an active material (surface body - solid). Then I prepared the porous section as a rectangle again and made a surface frozen (surface body - fluid).

During meshing, I just defined "Inlet", "oulet" and "well"

When I imported this to FLUENT, it does the same problem as yours. It creates a contact between fluid and porous media as a wall which I don't want. It should be as an interior.

So, can you please tell me how to get rid of this?

Regards,

Sabrina
Sabrinache is offline   Reply With Quote

Old   January 29, 2012, 01:53
Smile
  #5
New Member
 
ANTONY AROUL RAJ V
Join Date: Jan 2012
Location: Chennai
Posts: 16
Rep Power: 5
ANTONY A R V is on a distinguished road
I can give you solution to your problem in GAMBIT modeler.


You can go for volume split for 3D/face split for 2D, option to establish connectivity between porous and nonporus zone. If you do that and export to FLUENT you will you will get a shadow face ensuring the connectivity between porous and non porous zone.

My friend using ANSYS says that you can use 'slice volume' option to establish connectivity in the design modeler of ANSYS.

Try it out.
ANTONY A R V is offline   Reply With Quote

Old   March 15, 2012, 15:35
Default Porous wall
  #6
New Member
 
Akim Faisal
Join Date: Jan 2012
Posts: 18
Rep Power: 5
Akim679 is on a distinguished road
Hi,

I am trying to model a wall as a "Porous wall", is there a way to specify that using GAMBIT and FLUENT?

Thanks,
Akim
Akim679 is offline   Reply With Quote

Old   March 18, 2012, 11:32
Default porous wall
  #7
New Member
 
ANTONY AROUL RAJ V
Join Date: Jan 2012
Location: Chennai
Posts: 16
Rep Power: 5
ANTONY A R V is on a distinguished road
Porous media modelling is used for modelling two different phases of volume zone. I dont get about porous wall. could you eloborate.
ANTONY A R V is offline   Reply With Quote

Old   March 18, 2012, 12:04
Default Porous Jump
  #8
New Member
 
Akim Faisal
Join Date: Jan 2012
Posts: 18
Rep Power: 5
Akim679 is on a distinguished road
Hi,

Thanks for your reply. I have a 3D rectangular geometry, and I am trying to set the boundary condition of the bottom wall as a Porous jump in GAMBIT. However, when I read the mesh in FLUENT I get an error saying:
"Cannot change porous to porous-jump because
there is only one adjacent cell thread". I am not sure what this means or what I am doing wrong. Any help is appreciated.

Thanks,
Akim
Akim679 is offline   Reply With Quote

Old   March 31, 2012, 08:53
Default
  #9
New Member
 
Ciaran Hendry
Join Date: Mar 2012
Posts: 1
Rep Power: 0
chendry88 is on a distinguished road
@ Akim679,

Have you resolved this problem? How did you manage to do so, if you have?

Thanks
chendry88 is offline   Reply With Quote

Old   May 14, 2012, 09:26
Default
  #10
New Member
 
karthik
Join Date: Oct 2010
Posts: 14
Rep Power: 6
kitrax is on a distinguished road
Hi akim, the reason your model isnt working is because you need the face that you define as a porous jump to be connected to both volumes, you have probably only connected it to one volume...many people make/have made this error inlcuding myself...hope this helps
kitrax is offline   Reply With Quote

Old   August 10, 2012, 11:00
Default
  #11
New Member
 
Daan de Boer
Join Date: Jun 2012
Posts: 6
Rep Power: 0
daandb is on a distinguished road
I have done a similor case a few days ago. In addition to the named selection inlet and outlet faces I also created a names selections for the geometry of porous zone and the fluid zone. Hope this helps
daandb is offline   Reply With Quote

Old   September 5, 2012, 05:34
Default help
  #12
New Member
 
karl fisher
Join Date: Sep 2010
Posts: 7
Rep Power: 7
karl fisher is on a distinguished road
hi,

Anyone can send me his fluent project in order to compare the results of flow in porous media ?

Thanks

cuipdon_77@hotmail.com
karl fisher is offline   Reply With Quote

Old   September 7, 2012, 14:33
Default
  #13
Senior Member
 
zaynah K.
Join Date: Jun 2012
Location: Mauritius
Posts: 138
Rep Power: 5
zaynah04 is on a distinguished road
hi did anyone finally resolved that issue?

when i subtract the face which i want to be porous and define it as porous from my domain, and export to fluent i get the error messge,..

then i not subtract the face rather i just define it as porous_jump, but in fluent it is taking it as an entity..

please any help is more than welcome
zaynah
zaynah04 is offline   Reply With Quote

Old   September 25, 2012, 14:31
Default hi 4 u
  #14
New Member
 
yacine
Join Date: Jun 2011
Posts: 3
Rep Power: 6
yacprof is on a distinguished road
you have to create your geometry without declaring any thing but in fluent creat an udf in which you declare the porosity of the media. it's very very easy. i always use it in modeling catalytic reactors with catalytic porous zone. cordialy
yacprof is offline   Reply With Quote

Old   September 27, 2012, 11:06
Default
  #15
Member
 
Byron Smith R J
Join Date: Mar 2009
Location: India
Posts: 46
Rep Power: 8
byronsmith is on a distinguished road
Hai,
For creating a porous zone inside a volume, you can split zone inside fluent and that becomes an interior zone where you can apply the condition of porous.

For creating a porous jump, you need to create the volumes on either side of the wall and specify that as an wall and when defining you can use porous jump. Since porous jump uses darcys law to compute pressure loss, it requires cells on either side of the wall.

Try and let me know

with regards,
Byron
byronsmith is offline   Reply With Quote

Old   October 5, 2012, 12:06
Default Incline perforated plate
  #16
Member
 
Join Date: Sep 2011
Posts: 38
Rep Power: 5
Kamu is on a distinguished road
Does anyone have an idea of how I can model an inclined perforated plate using the porous jump B.C in FLUENT?

Last edited by Kamu; October 5, 2012 at 12:23.
Kamu is offline   Reply With Quote

Old   March 6, 2013, 12:03
Default
  #17
New Member
 
Join Date: Mar 2013
Posts: 8
Rep Power: 4
Leram is on a distinguished road
I am modelling a tube through which mixture of air and water passes and there is an air permeable membrane around the internal wall of the tube which is permeable to air only. I should model this as VOF in Fluent.

First, I need to set this wall boundary as Porous Jump in Gambit. I did the following steps in Gambit:

1) created a cylinder as volume
2) meshed it
3) set the boundaries as inflow, outflow, and porous jump (for the face around the cylinder)
4) set one fluid zone for the entire volume
5) export the mesh to Fluent

and when importing the mesh into Fluent, I got the Error Message : "Cannot change porous to porous-jump because there is only one adjacent cell thread".

Therefore, I tried the following procedure :

I created and two cylinders, one inside the other, and then define the surface of the inside cylinder as porous jump and the surface of the other as wall. But when exporting to Fluent, I just have one wall boundary in boundary conditions that are imported in Fluent. That is, Porous jump is missed!

I was wondering if you could help me define this problem? Much appriciated!

Thanks,
Leram

Last edited by Leram; March 7, 2013 at 01:43.
Leram is offline   Reply With Quote

Old   March 7, 2013, 01:16
Default
  #18
Member
 
Byron Smith R J
Join Date: Mar 2009
Location: India
Posts: 46
Rep Power: 8
byronsmith is on a distinguished road
Hai
In Gambit set the interior wall also as wall and export the mesh to Fluent. In fluent you can define the interior wall as porous jump. Try this and post your response

regards
Byron Smith
byronsmith is offline   Reply With Quote

Old   March 7, 2013, 01:42
Default
  #19
New Member
 
Join Date: Mar 2013
Posts: 8
Rep Power: 4
Leram is on a distinguished road
Quote:
Originally Posted by byronsmith View Post
Hai
In Gambit set the interior wall also as wall and export the mesh to Fluent. In fluent you can define the interior wall as porous jump. Try this and post your response

regards
Byron Smith
Hi Bryon,

Thanks for your Reply.

My problem is when I define this interior as wall, I cannot see Porous Jump in Type of BCs in Fluent infront of Wall Zone.



Leram
Leram is offline   Reply With Quote

Old   December 2, 2013, 04:19
Default
  #20
New Member
 
Musty
Join Date: Oct 2013
Posts: 8
Rep Power: 3
mustafa-uslu is on a distinguished road
Quote:
Originally Posted by Leram View Post
Hi Bryon,

Thanks for your Reply.

My problem is when I define this interior as wall, I cannot see Porous Jump in Type of BCs in Fluent infront of Wall Zone.



Leram
I have the similar problem at the moment, when I succeed I will let you know, if someone knows the solution please tell us
mustafa-uslu is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
modeling the fluid flow in porous media by Fluent Mohsen Nazari FLUENT 3 November 17, 2014 08:53
Porous Media efra FLUENT 2 April 10, 2007 01:46
Discrete phase model in porous media Pradeep FLUENT 0 February 3, 2006 17:30
Porous media and convergence A.Joshi FLUENT 0 October 21, 2003 22:09
porous media: Fluent or Star-CD? Igor Main CFD Forum 0 December 5, 2002 16:16


All times are GMT -4. The time now is 21:19.