Using a power law and Periodic boundary conditions along the streamwis direction for a simulation
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am0...@uah.edu
May 10, 2018, 12:24:45 PM5/10/18
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I have been trying to simulate a developed turbulent boundary layer flow over a flat surface using a Periodic condition along the stream-wise and the span-wise direction with a Power Law as an input to this simulation. I have tried two different methods to employ these condition and have failed to run it.
Method 1:
&MESH IJK=45,45,180, XB= 0,15.75,0,18,0,15, MULT_ID='mesh'/
&MULT ID='mesh', DX=15.75, I_UPPER=3/
&SURF ID='inlet' VEL=-6, PROFILE='ATMOSPHERIC', Z0=0.5, PLE=0.21, COLOR='BLUE' /
&VENT PBX=0, SURF_ID='inlet'/
&SURF ID='sky', FREE_SLIP=.TRUE., COLOR='INVISIBLE' /
&VENT PBX=0, SURF_ID='PERIODIC'/
&VENT PBX=63, SURF_ID='PERIODIC'/
&VENT PBY=0, SURF_ID='PERIODIC'/
&VENT PBY=18, SURF_ID='PERIODIC'/
&VENT PBZ=15, SURF_ID='sky'/
Method 1:
&MESH IJK=45,45,180, XB= 0,15.75,0,18,0,15, MULT_ID='mesh'/
&MULT ID='mesh', DX=15.75, I_UPPER=3/
&SURF ID='inlet' VEL=-6, PROFILE='ATMOSPHERIC', Z0=0.5, PLE=0.21, COLOR='BLUE' /
&SURF ID='sky', FREE_SLIP=.TRUE., COLOR='INVISIBLE' /
&VENT PBX=0, SURF_ID='inlet'/
&VENT PBX=15.75, SURF_ID='OPEN'/
&VENT PBX=31.5, SURF_ID='PERIODIC'/
&VENT PBX=63, SURF_ID='PERIODIC'/
&VENT PBY=0, SURF_ID='PERIODIC'/
&VENT PBY=18, SURF_ID='PERIODIC'/
&VENT PBZ=15, SURF_ID='sky'/
I would like to know if I am making any errors in setting up th input files and how to correct them for this particular case.
Any help is appreciated
Method 1:
&MESH IJK=45,45,180, XB= 0,15.75,0,18,0,15, MULT_ID='mesh'/
&MULT ID='mesh', DX=15.75, I_UPPER=3/
&SURF ID='inlet' VEL=-6, PROFILE='ATMOSPHERIC', Z0=0.5, PLE=0.21, COLOR='BLUE' /
&VENT PBX=0, SURF_ID='inlet'/
&SURF ID='sky', FREE_SLIP=.TRUE., COLOR='INVISIBLE' /
&VENT PBX=0, SURF_ID='PERIODIC'/
&VENT PBX=63, SURF_ID='PERIODIC'/
&VENT PBY=0, SURF_ID='PERIODIC'/
&VENT PBY=18, SURF_ID='PERIODIC'/
&VENT PBZ=15, SURF_ID='sky'/
Method 1:
&MESH IJK=45,45,180, XB= 0,15.75,0,18,0,15, MULT_ID='mesh'/
&MULT ID='mesh', DX=15.75, I_UPPER=3/
&SURF ID='inlet' VEL=-6, PROFILE='ATMOSPHERIC', Z0=0.5, PLE=0.21, COLOR='BLUE' /
&SURF ID='sky', FREE_SLIP=.TRUE., COLOR='INVISIBLE' /
&VENT PBX=0, SURF_ID='inlet'/
&VENT PBX=15.75, SURF_ID='OPEN'/
&VENT PBX=31.5, SURF_ID='PERIODIC'/
&VENT PBX=63, SURF_ID='PERIODIC'/
&VENT PBY=0, SURF_ID='PERIODIC'/
&VENT PBY=18, SURF_ID='PERIODIC'/
&VENT PBZ=15, SURF_ID='sky'/
I would like to know if I am making any errors in setting up th input files and how to correct them for this particular case.
Any help is appreciated
Kevin
May 10, 2018, 12:58:04 PM5/10/18
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The latest version of FDS (6.6.0) has special inputs for simulating winds. Your inputs are no longer recommended. Please use the latest parameters.
am0...@uah.edu
May 10, 2018, 1:19:23 PM5/10/18
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&SURF PROFILE='ATMOSPHERIC'/
&WIND U0=6, Z0=0.5, PLE=0.21/
!----!
&WIND U0=6, Z0=0.5, PLE=0.21/
!----!
&SURF ID='sky', FREE_SLIP=.TRUE., COLOR='INVISIBLE' /
&VENT PBX=0, SURF_ID='PERIODIC'/
&VENT PBX=63, SURF_ID='PERIODIC'/
&VENT PBY=0, SURF_ID='PERIODIC'/
&VENT PBY=18, SURF_ID='PERIODIC'/
&VENT PBZ=15, SURF_ID='sky'/
Is this the way you recommend?
Kevin
May 10, 2018, 2:04:58 PM5/10/18
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No. I recommend using Monin-Obhukov parameters. There are examples in the User's Guide. Also, look at the LNG Dispersion Experiments in the Validation Guide. Do not use ATMOSPHERIC profile or Z0 or PLE.
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