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

unsteady_Monitoring_Fluent ??

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 12, 2010, 11:41
Default unsteady_Monitoring_Fluent ??
  #1
New Member
 
Abdel
Join Date: Aug 2009
Posts: 2
Rep Power: 0
abenarous is on a distinguished road
Hi everybody,

I am simulating an unsteady flow around cylinder.

I have a problem to monitor (plot over time) a quantity(T,ux,uy,...) on a specified face (point, exit_area,...). I have just access to contours over time (animation) or surface integrals (volume weighted, surface weighted,...).

Please how to proceed.

Thanks in advance.

Abel
abenarous is offline   Reply With Quote

Old   April 16, 2010, 11:09
Default
  #2
New Member
 
Ertan Karaismail
Join Date: Apr 2009
Posts: 17
Rep Power: 7
ertan is on a distinguished road
Use 'Surface monitor' with 'vertex average' to monitor the time history of a variable at a point.

HTH

Last edited by ertan; April 16, 2010 at 11:12. Reason: to correct
ertan is offline   Reply With Quote

Old   May 9, 2010, 07:44
Default
  #3
Member
 
Daniel
Join Date: Apr 2010
Location: Manchester
Posts: 31
Rep Power: 6
drrbradford is on a distinguished road
I am looking to get time-dependent pressure coefficient details for each node along a surface. Is that possible?

The surface I am trying to get the data from is the solid in this animation:
http://www.youtube.com/watch?v=tWSt8wzKYrk

I would like to analyse the frequency of the pressure changes due to vortex shedding. If it is not possible to obtain the pressure data for all nodes, is it possible to specify particular points at which to monitor it? I am looking to compare my results with an experiment which had around 6/7 static pressure tappings.

Thanks.
drrbradford is offline   Reply With Quote

Old   May 9, 2010, 13:29
Default
  #4
New Member
 
Ertan Karaismail
Join Date: Apr 2009
Posts: 17
Rep Power: 7
ertan is on a distinguished road
To find the shedding frequency you may need to define a couple of points (1-3 points) in the area of interest. Then use 'surface monitor', with 'vertex averaged' pressure coefficient values (you can monitor, pressure or velocities as well). At user defined frequencies, FLUENT can plot monitored variables vs time graph and write them in separate files, which you can read with fluent again and make the FTT analysis to find the shedding frequency (or Strouhal number) .
ertan is offline   Reply With Quote

Old   May 9, 2010, 14:45
Default
  #5
Member
 
Daniel
Join Date: Apr 2010
Location: Manchester
Posts: 31
Rep Power: 6
drrbradford is on a distinguished road
Thanks, that's much appreciated and will definitely be of use for my Masters project.

Is there any way to export the data for use in other software (e.g. .csv or .dat for Matlab analysis)? I know the pressure data for all surface nodes is saved in .hmf metafiles so an animated, time-varying Cp graph can be produced and ideally the data in the metafiles that I'd like to be able to compile in a single .dat file or series of files to analyse.
drrbradford 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



All times are GMT -4. The time now is 09:55.