CFD Online Discussion Forums - Time averaging in Fluent

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Thanks for the post

This was a really useful post for Time averaged velocity plots in FLuent. I was looking for the answer for specific question discussed above. Thanks a lot

Quote:

Originally Posted by sbaffini (Post 360848)

I would definitely not follow what mentioned in the link. First, as you have the ability to let Fluent activate its statistics (and these are available at least from Fluent 6) you also have the way to retrieve them, which is very simple: go under contours, unsteady statistics and you're done.

These variables are also accessible by UDF (a little bit more cumbersome than usual)

However, let us suppose you don't have this statistics feature. I would not certainly save all the cas and dat i want to average. Instead it is much more convenient to have running averages, variances and covariances defined as UDM and update them at each time step

Edit: LuckyTran explined much better what i wanted to say. It's just that i started the reply more than a hour ago and then i got stucked in something else.

Hi,

Can you explain how exactly you can access the statistics variables through the UDF? I cannot find any MACRO to do that.. Any help would be appreciated..
Thanks in advance.

how to show time average vectors NOT by color ?

Quote:

Originally Posted by LuckyTran (Post 360755)

Did you enable data sampling before you started solving?

The data is stored in new variable names with either Mean or Rms at the end.

For example the instantaneous x-velocity, average x-velocity, and rms x-velocity are named, respectively:
X Velocity
X Velocity Mean
X Velocity Rms

any other variable that has statistics will also follow a similar nomenclature for the new variable names.

Hi, experts..

In ANSYS Fluent CFD, I applied data sampling for time statistics and got time average properties. Contours of time average properties is shown easily. but when I try to draw vectors of time average velocity, there is just a instantaneous vectors colored by *average velocity. I mean vectors do not change instantaneous to time average vectors. time average is shown by color only. here is only one option like *

Vectors of... velocity. phase.. water.. colored by..Unsteady Statistics.. Mean velocity Magnitude.. phase...water...

But, I need to show original time average vectors.

Please , guide me.. Thank you*

How to show Time Average velocity Vectors ? - ResearchGate. Available from: https://www.researchgate.net/post/Ho...locity_Vectors [accessed Mar 14, 2016].

Hi, experts..

In ANSYS Fluent CFD, I applied data sampling for time statistics and got time average properties. Contours of time average properties is shown easily. but when I try to draw vectors of time average velocity, there is just a instantaneous vectors colored by *average velocity. I mean vectors do not change instantaneous to time average vectors. time average is shown by color only. here is only one option like *

Vectors of... velocity. phase.. water.. colored by..Unsteady Statistics.. Mean velocity Magnitude.. phase...water...

But, I need to show original time average vectors.

Please , guide me.. Thank you

How to show Time Average velocity Vectors ? - ResearchGate. Available from: https://www.researchgate.net/post/Ho...locity_Vectors [accessed Mar 14, 2016].

If I understood you question correctly you just want to use the Custom Vectors option in the Vector tab and select the variables that you want to use for the components of your vector plot. The default choice is the instantaneous velocity components but you can switch to mean velocity components or whichever set of three variables you want to use in your vector plot.

Andrea

Quote:

Originally Posted by Andrea1984 (Post 589821)

very good and thank you.. yes, it is working... mean components X, Y, Z...

Quote:

Originally Posted by LuckyTran (Post 360755)

Hi, I need to calculate average time statistics for pressure about position or at time. what I need to do? thank you!