Hi,
I want to report a bug in "mean" module of FieldConvert for the 2.5D case. There is an issue in the computation of integral which comes from the error in the computation of "Domain volume". I am taking a test case for channel flow "ChanFlow_3DH1D_FFT.xml."
Here Lx = 1, Ly = 1, Lz = 1. So the volume should be 1. But the output depends upon the number of Fourier modes.
Below is the output with Nz = 20.
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Domain volume : 20
Integral (variable u) : 7.14583
Mean (variable u) : 0.357292
Integral (variable v) : 6.25
Mean (variable v) : 0.3125
Integral (variable w) : 5
Mean (variable w) : 0.25
Integral (variable p) : 10
Mean (variable p) : 0.5
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and this is one with Nz = 40.
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Domain volume : 40
Integral (variable u) : 14.2292
Mean (variable u) : 0.355729
Integral (variable v) : 12.5
Mean (variable v) : 0.3125
Integral (variable w) : 10
Mean (variable w) : 0.25
Integral (variable p) : 20
Mean (variable p) : 0.5
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Now, by changing the number of Fourier modes the "Domain volume" and "integral" should not change. However, the value of "mean" is correct; thus it seems there is some normalization issue. Similarly, I can see a discrepancy in the "innerproduct"
module as well. I have also attached the xml file for the reference.
With regards
Abhishek
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Abhishek Kumar
Assistant Professor (Research)
Centre for Fluid and Complex Systems
Coventry University, Coventry CV15FB
The United Kingdom
Phone: +44 24 7765 9150
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