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Old   June 3, 2013, 11:16
Default turbulent length scale
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Tobias Holzmann
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Hi all,

its a very simple question!

Is the turbulence length-scale in OpenFOAM based on the mixing-length ?

Its due to the fact of estimation of l

l = d_hyd * 0.038
l = d_hyd * 0.07


I am not 100% sure what to use.
In the past I thought that OF uses only the length-scale so I used always 0.038


Thanks in advance.
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Old   June 3, 2013, 11:24
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i dont know for what you need it excatly but for this BC

turbulentMixingLengthDissipationRateInlet

you need the mixinglength 0.07.
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Old   June 3, 2013, 11:34
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Hi,

thanks for your replay.

I just wanted to know how to calculate the the length scale for the cfd-online calculator:

http://www.cfd-online.com/Tools/turbulence.php


But thanks for your replay. So I think I need to set up the mixingLength (0.07) for the omega BC too.
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Old   July 23, 2013, 05:22
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Can you please provide me a reference from where you got the equations:
l = d_hyd * 0.038
l = d_hyd * 0.07

Thanks in advance.
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Old   July 23, 2013, 15:24
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Hi,

http://www.cfd-online.com/Wiki/Turbulence_length_scale
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Old   July 25, 2013, 01:01
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Thanks Tobi,
I had already seen that.
I am looking for a literature (text book / journal paper) reference and not a web-page reference.
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