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

Implement swirl as "internal" BC with calculated u_axial

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 27, 2011, 04:18
Default Implement swirl as "internal" BC with calculated u_axial
  #1
Member
 
don lenardo
Join Date: Nov 2010
Posts: 75
Rep Power: 6
lentschi is on a distinguished road
Hello everyone,

as you can see in the attched pdf-file, I want to calculate the case as follows:

A diffuser is determined in a water volume, the "global BCs" are the Velocity u=2m/s (Inlet) and p=0bar (Outlet). Now I want to implement a "swirl" as additional interior BC at an interface with the velocities (in cylindric coordinates) v_radial=1m/s and v_theta=0.8m/s, though v_axial should be the calculated u at this mentonoid interface!!
In fluent and OF it is possible to arranged that. But is this possible in CFX 13 too?And how can I implement it??

Thanks in advance.

Regards

Last edited by lentschi; October 27, 2011 at 04:47.
lentschi is offline   Reply With Quote

Old   October 27, 2011, 04:49
Default
  #2
Member
 
don lenardo
Join Date: Nov 2010
Posts: 75
Rep Power: 6
lentschi is on a distinguished road
Sorry, I forget the pdf....
Attached Files
File Type: pdf CFX.pdf (13.3 KB, 18 views)
lentschi is offline   Reply With Quote

Old   October 27, 2011, 06:13
Default
  #3
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
Sounds like this should just be a momentum source term. Look it up in the documentation.
ghorrocks is offline   Reply With Quote

Old   October 28, 2011, 07:16
Default
  #4
Member
 
don lenardo
Join Date: Nov 2010
Posts: 75
Rep Power: 6
lentschi is on a distinguished road
Hello,

thank you for your reply but there establish some problems with the momentum sources:

1) this is only for subdomains, not to use for Interfaces/BC (maybe I have overlook/missunderstood something)
2) I need velocities, not momentums


Regards
lentschi is offline   Reply With Quote

Old   October 28, 2011, 15:49
Default
  #5
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
To fix 1 you just make the entire domain a subdomain. But the second part of your question is the crux of the problem, I cannot think of a way to make it act only at the interface and in the correct direction.

Question 2 is fine, a momentum source can specify velocities. The "momentum" refers to what equation it applies to, not what is applied.
ghorrocks is offline   Reply With Quote

Old   November 2, 2011, 03:53
Default
  #6
Member
 
don lenardo
Join Date: Nov 2010
Posts: 75
Rep Power: 6
lentschi is on a distinguished road
OK,thank you for your answer!

Regards
lentschi is offline   Reply With Quote

Old   November 2, 2011, 05:58
Default
  #7
Member
 
D
Join Date: Nov 2010
Posts: 50
Rep Power: 6
bhatiadinesh is on a distinguished road
Are you trying to simulate something which actually physically exists ? if, yes, what is the actual arrangement there ?
bhatiadinesh 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
Howe to get swirl velocity component in 2D axisymtric swirl modeling Perra Fluent UDF and Scheme Programming 1 December 12, 2009 03:37
Swirl in Pressure Swirl Atomizer varunrajendra FLUENT 0 August 19, 2009 12:09
Quantifying Swirl Ianto Main CFD Forum 0 April 27, 2009 10:54
2d axisymmetric with swirl heather OpenFOAM Running, Solving & CFD 5 July 28, 2005 17:20
Swirl in backflow on pressure outlets Jonas Larsson FLUENT 17 February 3, 2000 03:14


All times are GMT -4. The time now is 19:55.