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

Multiple flows

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

Reply
 
LinkBack Thread Tools Display Modes
Old   May 7, 2012, 07:12
Default Multiple flows
  #1
New Member
 
Warren Wong
Join Date: May 2012
Posts: 2
Rep Power: 0
punoriginal is on a distinguished road
Hi all,

I want to simulate the following scenario (attached as a picture):

Water vapour and air enters a chamber through two separate inlets, and a mixture of water vapour and air exits a single outlet. I want the simulation to help me determine how much of the exiting flow is water vapour and how much is air. From laboratory experiments, it was found that the air flow is not enough to push all the water vapour out the inlet, and that some of the water vapour will (due to gravitational effects), condense and collect at the bottom of the chamber, building up over time. Is this scenario achievable with CFX? If so, I haven't been able to discover how, as I've always needed to specify the volume fraction of the materials at the outlet, which is inherently the information I want to find out from the simulation. Thanks!
Attached Images
File Type: jpg Chamber.jpg (26.6 KB, 25 views)
punoriginal is offline   Reply With Quote

Old   May 7, 2012, 17:20
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,646
Rep Power: 84
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Your specification of the composition at the outlet is probably from reverse flow at an opening - it would need to be specified there. But for an outlet or an opening in forward flow it is unspecified and is convected from the cells in the domain - which is what you want.

You need to identify exactly what physics is going on here. Does the water condense on the walls or some other feature? Or does it condense in the air and fall as rain? Is anything else happening? Once you know the physics you have then you can look at models to simulate it.
ghorrocks is offline   Reply With Quote

Old   May 7, 2012, 21:27
Default condensation
  #3
New Member
 
Warren Wong
Join Date: May 2012
Posts: 2
Rep Power: 0
punoriginal is on a distinguished road
Thanks for the reply. I know that some water vapour condenses on the walls but I do not know how much; this is one of the things I want to find out. That is, how much water vapour would collect in the chamber as a function of time. How do I go about specifying that water does condense on the walls, but that I do not know the amount?
punoriginal is offline   Reply With Quote

Old   May 8, 2012, 07:01
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,646
Rep Power: 84
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Have a look at the wall condensation models. These are quite advanced multiphase models so you will probably need to get some help or examples from CFX support to get it working.
ghorrocks is offline   Reply With Quote

Reply

Tags
chamber., condensation., mixing, multiple inlets, volume fraction.

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
how to set periodic boundary conditions Ganesh FLUENT 13 January 22, 2014 05:11
SIMPLE pressure correction in compressible flows Maarten de Jong Main CFD Forum 7 April 30, 2012 02:23
OpenFOAM static build on Cray XT5 asaijo OpenFOAM Installation 9 April 6, 2011 12:21
y+ in high Pr flows vishyaroon Main CFD Forum 0 April 15, 2010 14:24
Multiple domain/Multiple material problems... possible or not? Amiga500 OpenFOAM 1 April 14, 2010 15:32


All times are GMT -4. The time now is 07:09.