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-   -   Turbulence models (http://www.cfd-online.com/Forums/phoenics/66941-turbulence-models.html)

shineone July 29, 2009 00:50

Turbulence models
 
Hello everyone I am using Phoenics for studying wind environment in downtown area,
Could you please tell me which Turbulence model is better for evaluation of wind environment in downtown area?
I try to use the KEMMK in KE Variants, is that ok?
but i found it looks the same as KEMODL according the the constants in both of them,

also can i change the roughness parameter in the setting of this RANS model, i want to change it to 0.27 the same as i did in wind tunnel experiments.

Thank you very much for your help

phoenics_cfd July 29, 2009 10:57

statistical turbulence models for wind engineering
 
The Kato-Launder & Murakami et al variants of the k-e model are reported to perform better than the standard k-e model for flow around buildings. Both are available in PHOENICS, and they are documented here:

http://www.cham.co.uk/phoenics/d_pol...od/enc_mmk.htm

The empirical constants of the standard model are retained, but differences arise in the modelling practices, i.e. modified production rate or eddy-viscosity relationship. The main issue is to improve the representation of irrotational strain.

shineone July 30, 2009 01:16

Thank you
 
Thank you very much it is very helpful

maher9149 January 18, 2010 14:44

salut I want to enter the velocity like V=ax+b on a in a bubbly two phase flows




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