CFD Online Discussion Forums

CFD Online Discussion Forums (
-   FLUENT (
-   -   How to monitor a property at a certain set of coordinates?? (

behrang2009 February 16, 2010 21:30

How to monitor a property at a certain set of coordinates??
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 Monitors-Surface in Solve menu but that gives me the integral of a property over an area.

-mAx- February 17, 2010 02:00

create points (surface/points), and then solve/monitor (choose vertex average)

behrang2009 February 17, 2010 03:10

I'll give it a try.

behrang2009 February 18, 2010 00:28

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?

-mAx- February 18, 2010 02:06

if you mean a BC with a sinusoidal signal, you can use a profile or UDF

behrang2009 February 18, 2010 02:52

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?

-mAx- February 18, 2010 03:01

no idea, sorry.

behrang2009 March 2, 2010 22:48

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

-mAx- March 3, 2010 01:59

I never did that, but if you check the help, something may help you.
25.17.4 Postprocessing for Time-Dependent Problems:

The postprocessing of time-dependent data is similar to that for steady-state 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 root-mean-squares of the fluctuating values sampled during the calculation. The mean and root-mean-square (RMS) values for all solution variables will be available in the Unsteady Statistics... category of the variable selection drop-down 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

behrang2009 March 3, 2010 19:04

You mean FFT in the plot menu?

-mAx- March 4, 2010 02:29

I don't believe it is FFT (I don't have Fluent anymore, so I can't check)

behrang2009 March 4, 2010 02:49

thanks anyway

All times are GMT -4. The time now is 18:24.