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

Copying velocity field from one bc to another

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 27, 2006, 11:39
Default Copying velocity field from one bc to another
  #1
jorllam
Guest
 
Posts: n/a
Hi everybody,

I'm running a transient simulation in which, at the end of every time step, the velocity field from one boundary condition (an outlet bc with static pressure defined) must be the velocity profile for another boundary condition (an inlet bc with velocity profile defined) at the beginning of next time step. Both boundary condition surfaces have the same geometry and the same surface meshing (as if they were periodic), one is displaced from the other in the X axis direction.

I've tried to make it by creating user subroutines and junction box routines but it's being very hard to me knowing the data location used by the solver. Can anybody help me?

Thanks in advance!!
  Reply With Quote

Old   June 27, 2006, 20:33
Default Re: Copying velocity field from one bc to another
  #2
Robin
Guest
 
Posts: n/a
Make it a periodic. If they are just displaced in the X direction, it should work.
  Reply With Quote

Old   June 28, 2006, 02:59
Default Re: Copying velocity field from one bc to another
  #3
jorllam
Guest
 
Posts: n/a
Yes, the problem is these two bc's only share the velocity field, they have different pressure distributions. This is why I didn't set a periodic bc for these two bc's. I need to copy only the velocity profile at every time step.

Any other way of getting it?

Thank you anyway!
  Reply With Quote

Old   June 29, 2006, 11:54
Default Re: Copying velocity field from one bc to another
  #4
Robin
Guest
 
Posts: n/a
I see. Sounds like what you want is to model something that is linearly periodic, such as a tube bank or fully developed pipe flow. In version 11.0 you will be able to do this directly by specifying the mass flow rate or pressure rise across the periodic. In the current release (v10.0) the easiest way to do this is to specify a momentum source over your entire domain. The momentum source is essentially equal to your pressure drop. When you view the results, the pressure would essentially be the real pressure minus the pressure gradient.

Regards, Robin
  Reply With Quote

Old   June 30, 2006, 03:08
Default Re: Copying velocity field from one bc to another
  #5
jorllam
Guest
 
Posts: n/a
Yes, what I'm trying to model is something similar to a developed pipe flow. I think the best way to model it will be, as you said, placing a momentum source that makes the fluid recover the pressure drop. I hope this doesn't perturb very much the fluid velocity profile.

Thank you very much for your help Robin!

See you!
  Reply With Quote

Reply


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
real velocity field from energy spectrum Angel Main CFD Forum 7 December 13, 2013 21:40
accessing another velocity field in bc daviderzen OpenFOAM 0 April 20, 2011 07:24
Initial velocity field in StarCCM+ Subhadeep Siemens 3 December 21, 2008 04:40
Reconstruction of velocity and pressure field Jianglan Main CFD Forum 0 October 6, 2008 01:04
Velocity in Porous medium : HELP! HELP! HELP! Kali Sanjay Phoenics 0 November 6, 2006 07:10


All times are GMT -4. The time now is 11:23.