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-   -   High Turbulence Intensity Problem (http://www.cfd-online.com/Forums/fluent/71744-high-turbulence-intensity-problem.html)

bwg January 13, 2010 13:36

High Turbulence Intensity Problem
 
Hi All,

I am using the k-w SST turbulence model for a centrifugal compressor problem and am noticing that I get unphysically high values of turbulence intensity (hundreds, even thousands of percent in the mean flow). Looking into the problem, I set up a very simple simulation of a square duct with Y+ =30-50, with uniform inlet conditions without turbulence (I=0%). With this simple simulation, the mass-averaged turbulence intensity at outlet (about 10 widths downstream of inlet) was 109%, which I believe is unphysically high.

Has anyone else come across problems with unrealistically high values of turbulence intensity? If so, any suggestions on how to get around this problem would be much appreciated.

Thanks,

Ben

bwg January 13, 2010 14:09

I just realized the reason my turbulence intensities are so high is because I did not change the reference velocity, from which turbulence intensity is calculated. Problem solved.


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