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

droplet absorption diameter

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 31, 2010, 12:54
Default droplet absorption diameter
  #1
Member
 
Join Date: Mar 2009
Posts: 34
Rep Power: 8
Claudia is on a distinguished road
Hi,

I have a subdomain in which I want to remove particles from the domain. I know that I can use the "Absortion diameter". But now my question:

The absorption diameter depends on the gas velocity, is it possible to implement this dependency? I tried to do something like

absorption diameter = function of Velocity w,

but the following error occurs:

"Velocity w is not available for use in this term"

Does anyone has an idea?

Thanks in advance
Claudia
Claudia is offline   Reply With Quote

Old   March 31, 2010, 18:07
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,804
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
The message is quite clear - you can't make absorption diameter a function of W velocity. Some variables can only be constants or functions of a subset of variables and I think you have found one. If you really need to do this talk to CFX support and they may be able to find a work around for you.
ghorrocks is online now   Reply With Quote

Old   April 1, 2010, 02:15
Default
  #3
New Member
 
Alex
Join Date: Mar 2010
Location: Russia
Posts: 19
Rep Power: 7
a.m. is on a distinguished road
Send a message via ICQ to a.m.
try to create an expression in cfx pre like absorption diameter = f(velocity w), then use this expression in subdomain.

in expression you should use direct difinition, e.g.
"massflowave(Velocity W)@inlet*1[s]"
it means than your absorption diameter will be equal average velocity w in inlet BC
a.m. is offline   Reply With Quote

Old   April 1, 2010, 07:30
Default
  #4
Member
 
Join Date: Mar 2009
Posts: 34
Rep Power: 8
Claudia is on a distinguished road
Thanks, Glenn for your answer. So I have to tell the support about it and I hope they will find a workaround.
Claudia is offline   Reply With Quote

Old   April 2, 2010, 06:14
Default
  #5
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,804
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Yes, that's right. There will be a reason the absorption diameter cannot be set as a function of velocity. If you bypass the check, it may or may not affect your results - so talk to them and try to find out.
ghorrocks is online now   Reply With Quote

Reply

Tags
absorption, droplet, subdomain

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
maximum droplet diameter? antonietta FLUENT 1 February 23, 2006 07:41
Miminum diameter of droplet bk CD-adapco 0 July 12, 2005 06:54
Variable initial droplet diameter Sam FLUENT 0 June 4, 2005 11:36
spray droplet diameter David FLUENT 0 August 13, 2004 09:06
Significance of droplet diameter in multiphase flo Hbet FLUENT 0 June 14, 2001 09:36


All times are GMT -4. The time now is 19:12.