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

transport & diffusion sc. boundaries

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 25, 2005, 06:07
Default transport & diffusion sc. boundaries
  #1
Cirilo
Guest
 
Posts: n/a
Hi

some of you may have already read some similar messages, I have been trying to do this for quite some time and still trying to look if somebody out there could give me a hand.

Suppose you have defined two scalars, one of which is solved by the full transport equations (sc.1), the other one (sc.2) is solved by diffusion only. Now think of the domain as a 2D standard rectangular flow channel. Half of it is set as region 1 and the other half as region 2. In between these two regions there is a set of baffles cells with it respective baffle boundaries. At one end of the domain I have got an inlet boundary, where sc1 has a mass fraction of 1 and sc2 has a fixed mass fraction of 1, 100 or 1e6 if you wish (please bare that this scalar is solved by diffusion only, so you can set the value that you want). On the opposite side there is an outlet or a pressure boundary (up to you). I have set the baffle boundary to allow sc1 to flow through it and sc2 to have a zero flux at this boundary.

As far as I am concerned this settings would have to get the job done, but unfortunately they dont:

a) If I let these settings as they are, sc1 will flow only within region 1 and will not be able to flow across the baffle cells, which is not good! Whereas sc2 will diffuse only until it reaches the baffle boundary, which is good.

b) If I set the baffle boundary conditions to have 0 permeability and 100% porosity then sc1 will flow past it, which is good. But it will also let sc2 diffuse across it, which is not good!

Does anybody knows if this is possible to do in StarCD I know it can be done in CFX, but that is only because you can choose freely what to do with the A coefficients. I am pretty sure it can be done in Star but I don't know how. Please let me know if you have know anything that can be done.

Kind regards

Cirilo

ps sorry about the very long message
  Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
UDF and boundaries deneb FLUENT 1 October 24, 2008 04:32
Laminar diffusion flames and reactingFoam Transport properties jgaricano OpenFOAM Running, Solving & CFD 0 June 4, 2008 17:58
Pro-am boundaries Nalleli Siemens 1 July 13, 2005 02:08
boundaries of my project muhkiraz FLUENT 1 February 18, 2005 11:14
boundaries Peter Siemens 3 June 17, 2004 17:14


All times are GMT -4. The time now is 14:17.