CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Porous medium flow

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 7, 2007, 04:52
Default Hi, I am trying to simulate p
  #1
New Member
 
Shailesh Naire
Join Date: Mar 2009
Location: Keele, UK
Posts: 5
Rep Power: 8
shailesh is on a distinguished road
Hi,
I am trying to simulate porous medium flow using rhoPorousSimpleFoam. The geometry is a porous cylinder within another non-porous cylinder with inlet/outlet pipes. The problem I am having is in defining the porous zone required by the solver.

I am using Netgen to define and mesh the geometry. I defined 2 top-level-objects to differentiate between the porous zone and the rest but OF will not read more than 1 domain. I also tried fudging the Netgen mesh file to write everything as a single domain but extracting the element information for the porous zones. But, OF does not like that since a boundary condition is defined on internal edges.

Hope the above makes sense.
I have attached the Netgen geometry and mesh (Neutral format). Is there any obvious fix to this?
I am very new to OpenFoam so please be patient with me:-)
Many thanks in advance.
cheers,Shailesh
shailesh is offline   Reply With Quote

Old   August 7, 2007, 05:00
Default sorry i forgot to attach the f
  #2
New Member
 
Shailesh Naire
Join Date: Mar 2009
Location: Keele, UK
Posts: 5
Rep Power: 8
shailesh is on a distinguished road
sorry i forgot to attach the files.



shailesh is offline   Reply With Quote

Old   August 7, 2007, 05:04
Default sorry i forgot to attach the f
  #3
New Member
 
Shailesh Naire
Join Date: Mar 2009
Location: Keele, UK
Posts: 5
Rep Power: 8
shailesh is on a distinguished road
sorry i forgot to attach the files.

cylinderpipesporous.geo
shailesh is offline   Reply With Quote

Old   August 7, 2007, 05:06
Default The porous media works with a
  #4
Senior Member
 
Mark Olesen
Join Date: Mar 2009
Location: http://olesenm.github.io/
Posts: 777
Rep Power: 18
olesen will become famous soon enough
The porous media works with a single region, but needs cellZones. If you can convince Netgen to output a list of cells, you can make a cellZone quite easily.
olesen is offline   Reply With Quote

Old   August 7, 2007, 05:21
Default Mark, I tried fudging the Net
  #5
New Member
 
Shailesh Naire
Join Date: Mar 2009
Location: Keele, UK
Posts: 5
Rep Power: 8
shailesh is on a distinguished road
Mark,
I tried fudging the Netgen mesh file to do just this.
I initially meshed the geometry with 2 top-level objects which gave me the the elements to construct the CellZones. I then manually changed the domain nos. to a single domain and tried getting OF to convert it. But the problem then is that the slip BC patch on the inner cylinder surface is part of the internal mesh which I guess OF does not like.
does this make sense???
Shailesh
shailesh is offline   Reply With Quote

Old   August 7, 2007, 05:57
Default Here is an answer: 1) define
  #6
Senior Member
 
mkraposhin's Avatar
 
Matvej Kraposhin
Join Date: Mar 2009
Location: Moscow, Russian Federation
Posts: 172
Rep Power: 8
mkraposhin is on a distinguished road
Here is an answer:
1) define surface, which contains porousity volume in Netgen.
2) Mesh this surface and export it in .stl format
3) place .stl file in root of your case directory
4) open .stl file and write name (any symbols) in the first string, save it.
5) use cellSet to produce set of cells, that reliese on surface, (look in cellSetDict)
6) run setsToZones to produce cellZones
7) That's all!
And here is my question to you:
do you understand how to interpetate parameters of porousity:
e1/e2/3
d,f - for Darcy
c1,c2 - for Crosspowerlaw
mkraposhin is offline   Reply With Quote

Old   August 7, 2007, 06:11
Default thanks Kraposhin. i'll give th
  #7
New Member
 
Shailesh Naire
Join Date: Mar 2009
Location: Keele, UK
Posts: 5
Rep Power: 8
shailesh is on a distinguished road
thanks Kraposhin. i'll give that a try.
as for the porosity parameters,
e1,e2,and e3 define the anisotropy directions of the porous region.
definitions for d,f,c1,c2 can be found in porousZone.H.
hope this helps.
shailesh is offline   Reply With Quote

Old   August 7, 2007, 06:20
Default SORRY FOR BAD ENGLISH! Ok, i
  #8
Senior Member
 
mkraposhin's Avatar
 
Matvej Kraposhin
Join Date: Mar 2009
Location: Moscow, Russian Federation
Posts: 172
Rep Power: 8
mkraposhin is on a distinguished road
SORRY FOR BAD ENGLISH!
Ok, i understand this, but and i know, that d - is a viscous resistance (dzita/l) and f - is inertial resistance. and E.T() = (e1 e2 e3) have some common with permeability tensor. What is a form for simple porous geometry (row of tubes in chess-order)?
It would be nice to share some experience with you
mkraposhin is offline   Reply With Quote

Old   September 14, 2007, 05:18
Default Hi, anybody. I have to add a
  #9
Member
 
Paul Mauk
Join Date: Mar 2009
Posts: 39
Rep Power: 8
plmauk is on a distinguished road
Hi, anybody.
I have to add a porous zone to an existing mesh.
The geometry of the mesh is a cylinder.
How can I do that?

The question might be quite stupid, but I'm new in OpenFoam.
plmauk 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
Flow through porous medium Kiran AS FLUENT 6 September 16, 2011 07:38
Flow in porous medium Saba FLUENT 1 October 2, 2008 02:36
Flow through porous medium Kiran AS Main CFD Forum 1 August 31, 2006 08:12
gas flow through porous medium Shankar FLUENT 0 February 18, 2002 22:18
flow through a porous medium Vangelis Skaperdas Main CFD Forum 1 March 24, 1999 04:24


All times are GMT -4. The time now is 16:23.