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Pedestrian wind - steady state result fluctuations

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Old   May 24, 2016, 22:14
Default Pedestrian wind - steady state result fluctuations
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Hi all,

I have been simulating steady state pedestrian wind flow between buildings in a campus style geometry configuration from 16 wind directions in CFX and have been getting good convergence results with the current mesh, except for one wind direction.

I have attached the results for 8 monitoring points and they seem to oscillate indefinitely, even though the typical E-04 residual level has been reached earlier on.

What kind of issue do people think this is related to? Numerical? Mesh density? Any suggestions are welcome.


Thanks
Attached Images
File Type: png WNW monitoring points.PNG (65.2 KB, 15 views)
File Type: png WNW residuals.PNG (36.5 KB, 12 views)
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Old   May 25, 2016, 02:55
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This is typical where a steady state simulation is in fact transient, as large scale transient structures are being formed. You would expect this in the wake of bluff objects like buildings so this is no surprise.

So the fix is to do a transient simulation.
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