Easy way to export monitor data from CFX out file

jonny_b · July 11, 2012, 13:02

Hey guys,

I would like to do an FFT analysis to determine the frequency spectrum in my solution. I know that I should be able to export time dependent variable data from CFD-Post, but the problem is the time step interval for which I've captured data in trn files is too large to extract a meaningful frequency analysis. I've set up monitors of pressure and I know that this information is contained in my monitors for every time step. Is there an easy way to extract monitor information so that I can import it into Matlab and do my FFT analysis there? I can't seem to find out how to get this data in CFD-Post.

Thanks,
Jonathan

jonny_b · July 11, 2012, 13:20

Nevermind found out how to extract monitor info from a .res file.

Quote:

After the CFX-Solver has finished, the monitor point data (if the monitor point information is required) is extracted from a .res file using the cfx5dfile command. The following syntax is used:

cfx5dfile <file> -read-monitor

where <file> is a CFX-Solver input or results file containing monitor point information. The output is sent to standard output (you may want to add a redirect to write the output to a text file, for example:

cfx5dfile <file> -read-monitor > out.txt

The output is produced as a list of variable names, followed by a comma-delimited list of values that correspond to the order of variable names. One line of these values is produced for every iteration that has been carried out.

monkey1 · July 12, 2012, 03:00

Can do it even easier. If you're using the solver manager of ansys, then just open your case in the manager (open completed run). As you sepcified Monitors for the run you will then see a monitors tab. Within this tab just right click on the graph and select "Export Plot Data". It will then write a .csv file with all the data in the monitor graph.

jonny_b · July 17, 2012, 14:53

Holy cow Monkey! I didn't even think about that. That is easy! Thanks for the advice. You just made my life a lot easier.

monkey1 · July 18, 2012, 05:08

Always glad when I can help

jonny_b · August 2, 2012, 08:34

I also found another usefull CFX command although I still think that monkey1's suggestion may be the quickest. This terminal command looks like it provides a lot of options however :

Quote:

Name: cfx5mondata

Purpose:

Run the CFX Monitor Data Exporter. Monitor data will be output in
Excel-compatible CSV (comma-separated values) format

Synopsis:

cfx5mondata -res <file> | -dir <directory> | -mon <file>
[-showvars] [-nocoeffloops] [-lastvalueonly]
[-varlist <variables>] [-varrule <rule>]
[-out <file>] [-help] [-v]

Badi · April 24, 2013, 07:22

Sorry for exhuming this old thread.
When I try to export my data into csv all I got are the timesteps and not my mesh movement. Is this a common problem?

monkey1 · April 24, 2013, 08:00

Hi Badi!
I do not exactly understand what you want to do. If you are exporting Monitor Point data you will always get only the time steps with the corresponding values of the monitored data without any info about the mesh. It's just exporting 2D Chart Data.
What exactly do you want to do?

Badi · April 24, 2013, 08:06

yeah I know, I had a monitor point on a moving wall. It did monitor the movement in y (periodic movement). I basically had a sinus curve.
The problem was i only got the data from the x curve and not the y curve.

I dont know if it is a bug but this only happens when you make a new monitor, while solving, with the new point.
If I export the data from the "standart" User points tab I get all the data... weird

monkey1 · April 24, 2013, 08:13

Weird...just tried it on a simulation that is running with the standard monitor point tab "User Points" and a newly created monitor tab "Plot Monitor 1" and for both the .csv file contained all the data displayed...

ghorrocks · April 25, 2013, 07:03

Just checking - it is not that you simply have to zoom in on the region of interest to see something happen? Also, have you checked the resolution of the numbers in the CSV file is sufficient to show the signal you expect to see?

bitak · July 26, 2013, 12:29

Helo all.
How I can export data from one point from CFX post?
in fact I define point in CFX post and my purpose is maximum value of special parameter.
How I can see result?

ghorrocks · July 27, 2013, 07:16

Have a look at the CFX reference guide for available CEL functions. The probe function is the one you want.

elaf_2003 · September 26, 2013, 19:51

Hi mates
I ,d like to monitor the point with cluster for fluent case for instance Cm or velocity or residual, so how I can monitor these issues.
regard

ghorrocks · September 26, 2013, 20:05

Try the fluent forum.

elaf_2003 · September 26, 2013, 20:10

thanks mate
could you more explain.
regard

ghorrocks · September 26, 2013, 20:12

This is the CFX forum.

This is the link to the Fluent forum: http://www.cfd-online.com/Forums/fluent/

Lilienthal · October 23, 2013, 06:34

Hello all,

first post for me in this forum, so I hope I found the right thread.

Is there any way to monitor Expressions along a line in the CFX Solver Manager?
The manual tells me its only possible to monitor Expressions on a x,y,z-point or a mesh region like a boundary or inlet.
Is it possible to circumnavigate that restriction in user fortran i.e.?

Btw.: replacing a line with a huge number of monitor points is not what I want to do.

Any ideas would be appriciated...

ghorrocks · October 23, 2013, 07:01

What do you want to do with the line?

I know of no way to do stuff along a line in the solver. It is easy in post-processing.

Lilienthal · October 23, 2013, 08:01

I would like to monitor the fluid height in steady state stratified two-phase flow simulation.
It has to be at a certain line for comparison with experiment.

For comparison with the experimental data its sufficient to check the level in CFD Post. But for checking if its
really steady, it has to be monitored in the solver.

July 11, 2012, 13:02	Easy way to export monitor data from CFX out file	#1
jonny_b Member jonathan Join Date: Jun 2009 Posts: 47 Rep Power: 17	Hey guys, I would like to do an FFT analysis to determine the frequency spectrum in my solution. I know that I should be able to export time dependent variable data from CFD-Post, but the problem is the time step interval for which I've captured data in trn files is too large to extract a meaningful frequency analysis. I've set up monitors of pressure and I know that this information is contained in my monitors for every time step. Is there an easy way to extract monitor information so that I can import it into Matlab and do my FFT analysis there? I can't seem to find out how to get this data in CFD-Post. Thanks, Jonathan

July 12, 2012, 03:00		#3
monkey1 Senior Member Join Date: Jul 2011 Location: Berlin, Germany Posts: 173 Rep Power: 14	Can do it even easier. If you're using the solver manager of ansys, then just open your case in the manager (open completed run). As you sepcified Monitors for the run you will then see a monitors tab. Within this tab just right click on the graph and select "Export Plot Data". It will then write a .csv file with all the data in the monitor graph. jonny_b, pz21, presidentmamun and 1 others like this.

July 26, 2013, 12:29	export point in CFX post	#12
bitak Member bitak Join Date: Jul 2009 Posts: 56 Rep Power: 16	Helo all. How I can export data from one point from CFX post? in fact I define point in CFX post and my purpose is maximum value of special parameter. How I can see result?

September 26, 2013, 19:51	point monitor	#14
elaf_2003 New Member elaf Join Date: May 2013 Posts: 15 Rep Power: 12	Hi mates I ,d like to monitor the point with cluster for fluent case for instance Cm or velocity or residual, so how I can monitor these issues. regard

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July 17, 2012, 14:53		#4
jonny_b Member jonathan Join Date: Jun 2009 Posts: 47 Rep Power: 17	Holy cow Monkey! I didn't even think about that. That is easy! Thanks for the advice. You just made my life a lot easier.

July 18, 2012, 05:08		#5
monkey1 Senior Member Join Date: Jul 2011 Location: Berlin, Germany Posts: 173 Rep Power: 14	Always glad when I can help

April 24, 2013, 07:22		#7
Badi Member Sebastian Join Date: Apr 2013 Posts: 31 Rep Power: 13	Sorry for exhuming this old thread. When I try to export my data into csv all I got are the timesteps and not my mesh movement. Is this a common problem?

April 24, 2013, 08:00		#8
monkey1 Senior Member Join Date: Jul 2011 Location: Berlin, Germany Posts: 173 Rep Power: 14	Hi Badi! I do not exactly understand what you want to do. If you are exporting Monitor Point data you will always get only the time steps with the corresponding values of the monitored data without any info about the mesh. It's just exporting 2D Chart Data. What exactly do you want to do?

April 24, 2013, 08:06		#9
Badi Member Sebastian Join Date: Apr 2013 Posts: 31 Rep Power: 13	yeah I know, I had a monitor point on a moving wall. It did monitor the movement in y (periodic movement). I basically had a sinus curve. The problem was i only got the data from the x curve and not the y curve. I dont know if it is a bug but this only happens when you make a new monitor, while solving, with the new point. If I export the data from the "standart" User points tab I get all the data... weird

April 24, 2013, 08:13		#10
monkey1 Senior Member Join Date: Jul 2011 Location: Berlin, Germany Posts: 173 Rep Power: 14	Weird...just tried it on a simulation that is running with the standard monitor point tab "User Points" and a newly created monitor tab "Plot Monitor 1" and for both the .csv file contained all the data displayed...

April 25, 2013, 07:03		#11
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Just checking - it is not that you simply have to zoom in on the region of interest to see something happen? Also, have you checked the resolution of the numbers in the CSV file is sufficient to show the signal you expect to see?

July 27, 2013, 07:16		#13
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Have a look at the CFX reference guide for available CEL functions. The probe function is the one you want.

September 26, 2013, 20:05		#15
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Try the fluent forum.

September 26, 2013, 20:10		#16
elaf_2003 New Member elaf Join Date: May 2013 Posts: 15 Rep Power: 12	thanks mate could you more explain. regard

September 26, 2013, 20:12		#17
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	This is the CFX forum. This is the link to the Fluent forum: http://www.cfd-online.com/Forums/fluent/

October 23, 2013, 06:34		#18
Lilienthal New Member Paul Join Date: Oct 2013 Posts: 4 Rep Power: 12	Hello all, first post for me in this forum, so I hope I found the right thread. Is there any way to monitor Expressions along a line in the CFX Solver Manager? The manual tells me its only possible to monitor Expressions on a x,y,z-point or a mesh region like a boundary or inlet. Is it possible to circumnavigate that restriction in user fortran i.e.? Btw.: replacing a line with a huge number of monitor points is not what I want to do. Any ideas would be appriciated...

October 23, 2013, 07:01		#19
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	What do you want to do with the line? I know of no way to do stuff along a line in the solver. It is easy in post-processing.

October 23, 2013, 08:01		#20
Lilienthal New Member Paul Join Date: Oct 2013 Posts: 4 Rep Power: 12	I would like to monitor the fluid height in steady state stratified two-phase flow simulation. It has to be at a certain line for comparison with experiment. For comparison with the experimental data its sufficient to check the level in CFD Post. But for checking if its really steady, it has to be monitored in the solver.