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Trnavg or Mean?? for Time averaging

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Old   December 9, 2013, 22:21
Default Trnavg or Mean?? for Time averaging
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Hi all,
I need time-averaged vorticity of certain plane for comparing my simulation.

So I emoloyed "Data Sampling For Time Statistics" to avarage variables buy realized that there isn't vorticity magnitude in sampling variables.

So I made Custom Field Function made by just "vorticity magnitude" expression. And also made Custom function of velocity maginitude for test.

And I added it in Sampling Options and ran simulations for some times.

I export mean value of custom function(velocity,vorticity) by CFD-POST format, and found that there are three time-average variable type (Trnavg, mean, rms)

Custom Variables has mean, rms type and
basic variables(such total pressure, velocity etc..) has Trnave,Trnrms

I thought Mean of Custom variables equals to Trnave of basic variables,
but found that there was a little discrepancy between them(see Pics, this is 2D sample of simulation to establish method of Data Sampling).
(basic Velocity.Trnavg between Mean Custom Function from Velocity Mag.)

So, my question is,
What is different between Trnavg and Mean value?
Which one is regarded as Time-Avaraged value?

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Old   December 10, 2013, 03:12
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This is just a guess, but could it be that the averaging interval is not the same for both variables?
When you say that you added the custom functions later to your simulation, did you start the simulation all over again or did you just continue from a point where the standard output variables had already been sampled?
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