Average study of RANS results

serrar · April 26, 2019, 07:23

Hi expert,
I recorded .data and .cas files of a turbulent flow with a RANS model and transient every 10-time steps. Now, I want to do an average study of these files, for example, 10 files per post-processing.
is it possible?
Best regards,

LuckyTran · April 26, 2019, 10:48

Yes and no.

Yes: you should have activated the data sampling for time statistics option before you did the simulation.

No: you can't do it after the fact. You need to re-run it. Or you write your own code that does the averaging.

serrar · April 26, 2019, 11:07

Dear LuckyTran,
-----------------------------------------------------------------------------------
Yes: you should have activated the data sampling for time statistics option before you did the simulation.
-----------------------------------------------------------------------------------
For this answer how can I do these steps using FLUENT?

Best regards,

LuckyTran · April 26, 2019, 11:31

In the GUI, in the same place where you can find the calculate button.

There is a checkbox.

Google is your friend.

serrar · April 26, 2019, 11:57

Dear LuckyTran,
Thank you very much for your quick response, which allowed me to start my studies. If possible, I need more details. I have :
My time interval [0, 0.3] and I want to save the values every 10 steps with:
time step size = 5e-5
Number f time step = 6000
What good values can I have in:
sampling Interval?
Sampling option?
Best regards,

LuckyTran · April 26, 2019, 12:10

sampling interval 10 means it adds the values to the average every 10 time-steps

sampling options are options. If you want to use them, you can use them. If not, don't.

Read the guide!

serrar · April 26, 2019, 13:23

Dear LuckyTran,

I followed your advice, but after which iterations the code that diverges. Do you have help to dislodge the situation?
-----------------------------------------------------------------------------------------
Divergence detected in AMG solver: x-momentum
Divergence detected in AMG solver: y-momentum
Divergence detected in AMG solver: pressure correction
Divergence detected in AMG solver: k
Divergence detected in AMG solver: omega
Divergence detected in AMG solver: x-momentum
Divergence detected in AMG solver: y-momentum
Divergence detected in AMG solver: pressure correction
Divergence detected in AMG solver: k
Divergence detected in AMG solver: omega
Divergence detected in AMG solver: x-momentum
Divergence detected in AMG solver: y-momentum
Divergence detected in AMG solver: pressure correction
Divergence detected in AMG solver: k
Divergence detected in AMG solver: omega
reversed flow in 49 faces on pressure-outlet 7.

Divergence detected in AMG solver: x-momentum
Divergence detected in AMG solver: y-momentum
Divergence detected in AMG solver: pressure correction
Divergence detected in AMG solver: k
Divergence detected in AMG solver: omega
Error at host: floating point exception

Error at Node 0: floating point exception

Error at Node 1: floating point exception

Error at Node 2: floating point exception

Error at Node 3: floating point exception

Error: floating point exception
Error Object: #f
-----------------------------------------------------------------------------------------

Quote:

PHP Code:


			
[ATTACH]69630[/ATTACH]



[ATTACH]69631[/ATTACH]

April 26, 2019, 07:23	Average study of RANS results	#1
serrar Member Join Date: Sep 2018 Posts: 31 Rep Power: 8	Hi expert, I recorded .data and .cas files of a turbulent flow with a RANS model and transient every 10-time steps. Now, I want to do an average study of these files, for example, 10 files per post-processing. is it possible? Best regards,

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Real results from a simple study WHAT am I doing wrong?	jon g	FloEFD, FloWorks & FloTHERM	5	November 14, 2018 10:46
Results from RANS and LES look completely different	ssa_cfd	OpenFOAM Running, Solving & CFD	7	September 27, 2018 08:17
Comparing Air numerical results with water experimental results	cristian2009es	Main CFD Forum	1	July 2, 2014 19:11
RANS from time average -- How about space average?	TT	Main CFD Forum	1	April 11, 2006 15:38
Listing Average Results	Deepak	Siemens	2	March 14, 2006 02:22

April 26, 2019, 10:48		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,754 Rep Power: 66	Yes and no. Yes: you should have activated the data sampling for time statistics option before you did the simulation. No: you can't do it after the fact. You need to re-run it. Or you write your own code that does the averaging.

April 26, 2019, 11:07		#3
serrar Member Join Date: Sep 2018 Posts: 31 Rep Power: 8	Dear LuckyTran, ----------------------------------------------------------------------------------- Yes: you should have activated the data sampling for time statistics option before you did the simulation. ----------------------------------------------------------------------------------- For this answer how can I do these steps using FLUENT? Best regards,

April 26, 2019, 11:31		#4
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,754 Rep Power: 66	In the GUI, in the same place where you can find the calculate button. There is a checkbox. Google is your friend.

April 26, 2019, 11:57		#5
serrar Member Join Date: Sep 2018 Posts: 31 Rep Power: 8	Dear LuckyTran, Thank you very much for your quick response, which allowed me to start my studies. If possible, I need more details. I have : My time interval [0, 0.3] and I want to save the values every 10 steps with: time step size = 5e-5 Number f time step = 6000 What good values can I have in: sampling Interval? Sampling option? Best regards,

April 26, 2019, 12:10		#6
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,754 Rep Power: 66	sampling interval 10 means it adds the values to the average every 10 time-steps sampling options are options. If you want to use them, you can use them. If not, don't. Read the guide!