Time Averaged Solution from CFX for Transient Data

AS_Aero · April 11, 2017, 03:43

Hi All

I have a doubt regarding time averaging my transient data when I am running LES simulation. I dint give that option in my definition file while I was creating the case setup. But now I have some transient data of which I need to take a statistical average of it. How is it possible ? Or is it possible to do ??

ghorrocks · April 11, 2017, 19:41

When I do LES simulations I generally set up monitor points and do my own post-processing to determine flow statistics.

AS_Aero · April 12, 2017, 07:33

So you basically take the monitor point values and then average them outside CFX , using some Matlab or Python etc ? I saw there is an option in CFX solver control where we can give arithematic averaging but then I must give this before the case is started to run. But
now I dint do that and now I have to do an averaging which I have no idea how I could do it. And the .res file from LES solution is showing me the last transient results.

ghorrocks · April 12, 2017, 08:07

The most common type of averaging in LES is temporal averaging, and to do that you need a full time history for the duration of interest.

Note there are other forms of averaging, such as ensemble averaging and spatial averaging which are useful for LES in some circumstances. Some of these do not need a full time history.

AS_Aero · April 12, 2017, 09:30

So How do you do this time Averaging is the question !! Is it directly in CFD Post or using someother software ?

ghorrocks · April 12, 2017, 18:46

I do it in other software.

AS_Aero · April 13, 2017, 04:51

ok perfect.

April 11, 2017, 03:43	Time Averaged Solution from CFX for Transient Data	#1
AS_Aero Senior Member Join Date: Mar 2013 Location: Germany Posts: 357 Rep Power: 14	Hi All I have a doubt regarding time averaging my transient data when I am running LES simulation. I dint give that option in my definition file while I was creating the case setup. But now I have some transient data of which I need to take a statistical average of it. How is it possible ? Or is it possible to do ??

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April 11, 2017, 19:41		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,728 Rep Power: 143	When I do LES simulations I generally set up monitor points and do my own post-processing to determine flow statistics.

April 12, 2017, 07:33		#3
AS_Aero Senior Member Join Date: Mar 2013 Location: Germany Posts: 357 Rep Power: 14	So you basically take the monitor point values and then average them outside CFX , using some Matlab or Python etc ? I saw there is an option in CFX solver control where we can give arithematic averaging but then I must give this before the case is started to run. But now I dint do that and now I have to do an averaging which I have no idea how I could do it. And the .res file from LES solution is showing me the last transient results.

April 12, 2017, 08:07		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,728 Rep Power: 143	The most common type of averaging in LES is temporal averaging, and to do that you need a full time history for the duration of interest. Note there are other forms of averaging, such as ensemble averaging and spatial averaging which are useful for LES in some circumstances. Some of these do not need a full time history.

April 12, 2017, 09:30		#5
AS_Aero Senior Member Join Date: Mar 2013 Location: Germany Posts: 357 Rep Power: 14	So How do you do this time Averaging is the question !! Is it directly in CFD Post or using someother software ?

April 12, 2017, 18:46		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,728 Rep Power: 143	I do it in other software.

April 13, 2017, 04:51		#7
AS_Aero Senior Member Join Date: Mar 2013 Location: Germany Posts: 357 Rep Power: 14	ok perfect.