unsteady_Monitoring_Fluent ??

abenarous · April 12, 2010, 11:41

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

ertan · April 16, 2010, 11:09

Use 'Surface monitor' with 'vertex average' to monitor the time history of a variable at a point.

HTH

drrbradford · May 9, 2010, 07:44

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.

ertan · May 9, 2010, 13:29

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) .

drrbradford · May 9, 2010, 14:45

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.

April 12, 2010, 11:41	unsteady_Monitoring_Fluent ??	#1
abenarous New Member Abdel Join Date: Aug 2009 Posts: 2 Rep Power: 0	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

April 16, 2010, 11:09		#2
ertan New Member Ertan Karaismail Join Date: Apr 2009 Posts: 17 Rep Power: 17	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

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May 9, 2010, 07:44		#3
drrbradford Member Daniel Join Date: Apr 2010 Location: Manchester Posts: 30 Rep Power: 15	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.

May 9, 2010, 13:29		#4
ertan New Member Ertan Karaismail Join Date: Apr 2009 Posts: 17 Rep Power: 17	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) .

May 9, 2010, 14:45		#5
drrbradford Member Daniel Join Date: Apr 2010 Location: Manchester Posts: 30 Rep Power: 15	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.