
[Sponsors] 
February 16, 2010, 21:30 
How to monitor a property at a certain set of coordinates??

#1 
Member
Behrang Asgharian
Join Date: Oct 2009
Posts: 38
Rep Power: 7 
Guys!
During an unsteady iteration, how can I get the property (T,P,...) at certain x,y and draw a plot of it versus time? I have used MonitorsSurface in Solve menu but that gives me the integral of a property over an area. Thanks 

February 17, 2010, 02:00 

#2 
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,973
Rep Power: 30 
create points (surface/points), and then solve/monitor (choose vertex average)
__________________
In memory of my friend Hervé: CFD engineer & freerider 

February 17, 2010, 03:10 

#3 
Member
Behrang Asgharian
Join Date: Oct 2009
Posts: 38
Rep Power: 7 
Thanks
I'll give it a try. 

February 18, 2010, 00:28 

#4 
Member
Behrang Asgharian
Join Date: Oct 2009
Posts: 38
Rep Power: 7 
Thanks a million. It worked!!
Can I ask you another question? How can I have a variable initial condition like a sinusoidal pressure throughout the domain I mean for example p=p(x)? How can we have variable body force throughout the domain? Last edited by behrang2009; February 18, 2010 at 00:44. 

February 18, 2010, 02:06 

#5 
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,973
Rep Power: 30 
if you mean a BC with a sinusoidal signal, you can use a profile or UDF
__________________
In memory of my friend Hervé: CFD engineer & freerider 

February 18, 2010, 02:52 

#6 
Member
Behrang Asgharian
Join Date: Oct 2009
Posts: 38
Rep Power: 7 
I mean how I can put the pressure sinusoidally on the cells throughout the domain. Take a narrow tube for example that pressure changes along x axis but constant at every cross section. I want to use this as an initial condition and let the flow oscillate.
I have used UDF in a different way (DEFINE_PROFILE) and kind of got what I wanted. I wonder if we can impose such an initial condition on the cells or not. DEFINE_PROFILE is used for faces. Is there any Macro that we can use for the domain? Thanks 

February 18, 2010, 03:01 

#7 
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,973
Rep Power: 30 
no idea, sorry.
__________________
In memory of my friend Hervé: CFD engineer & freerider 

March 2, 2010, 22:48 

#8 
Member
Behrang Asgharian
Join Date: Oct 2009
Posts: 38
Rep Power: 7 
Hi Again!
Since you helped last time, I think you know the answer to the following question of mine: I am modeling oscillating flow which is naturally unsteady. I need to integrate some field functions over one period T. In what menu can I such an option? Thanks Good luck Behrang 

March 3, 2010, 01:59 

#9 
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,973
Rep Power: 30 
I never did that, but if you check the help, something may help you.
******** 25.17.4 Postprocessing for TimeDependent Problems: The postprocessing of timedependent data is similar to that for steadystate data, with all graphical and alphanumeric commands available. You can read a data file that was saved at any point in the calculation (by you or with the autosave option) to restore the data at any of the time levels that were saved. FLUENT will label any subsequent graphical or alphanumeric output with the time value of the current data set. If you save data from the force or surface monitors to files (see step 5 in Section 25.17.1), you can read these files back in and plot them to see a time history of the monitored quantity ... If you enabled the Data Sampling for Time Statistics option in the Iterate panel, FLUENT will compute the time average (mean) of the instantaneous values and rootmeansquares of the fluctuating values sampled during the calculation. The mean and rootmeansquare (RMS) values for all solution variables will be available in the Unsteady Statistics... category of the variable selection dropdown list that appears in postprocessing panels. You can set the Sampling Interval such that Data Sampling for Time Statistics can be performed at the specified frequency
__________________
In memory of my friend Hervé: CFD engineer & freerider 

March 3, 2010, 19:04 

#10 
Member
Behrang Asgharian
Join Date: Oct 2009
Posts: 38
Rep Power: 7 
Thanks
You mean FFT in the plot menu? 

March 4, 2010, 02:29 

#11 
Super Moderator
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,973
Rep Power: 30 
I don't believe it is FFT (I don't have Fluent anymore, so I can't check)
__________________
In memory of my friend Hervé: CFD engineer & freerider 

March 4, 2010, 02:49 

#12 
Member
Behrang Asgharian
Join Date: Oct 2009
Posts: 38
Rep Power: 7 
thanks anyway


Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
OF 1.6  Ubuntu 9.10 (64bit)  GLIBCXX_3.4.11 not found  piprus  OpenFOAM Installation  22  February 25, 2010 14:43 
Help with GNUPlot  Renato.  Main CFD Forum  6  June 6, 2007 19:51 
Env variable not set  gruber2  OpenFOAM Installation  5  December 30, 2005 05:27 
How to set environment variables  kanishka  OpenFOAM Installation  1  September 4, 2005 10:15 
how to set chemical property in porous region?  tt  CFX  1  January 4, 2004 23:49 