Pedestrian wind - steady state result fluctuations

galagala · May 24, 2016, 22:14

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

ghorrocks · May 25, 2016, 02:55

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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May 25, 2016, 02:55		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	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.