CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Wiki > Talk:Turbulence modeling

Talk:Turbulence modeling

From CFD-Wiki

(Difference between revisions)
Jump to: navigation, search
(low-re models and heat trasfer coefficients)
(All technical questions are to be directed to one of the CFD-Online forums. The talk pages are related to editing issues for CFDWiki sections)
 
Line 1: Line 1:
-
Hi
 
-
I'm working on oil distribution analysis. My flow model consists on small passages (diam. 4 mm)
 
-
and I have to run a steady-state analysis with a commercial Code. Re number is about 12000. Flow enters
 
-
from a circular tube (Inlet b.cond.) and exit from two ducts (Pressure b. cond)
 
-
1) I cannot use k-eps high-Re with wall function because I should use a 0.8-1 mm cell at wall
 
-
in order to have correct y+ (30-100).
 
-
2) Then I tried to use both two layer models and k-eps low-Re/Hybrid Wall Function with a proper fine
 
-
mesh at wall (15 layers with y+ less than  1).
 
-
I do not know if the second way is correct or not. I can only say that by using the last two turbulence models
 
-
3) I found some strange values for heat transfer coefficients at wall, about 24000-30000 W/m2 K while proper
 
-
values should be 4000-5000 W/m2 K
 
-
Could anyone tell me why I found so high heat trasfer coefficients and if low-Re models are correct or not
 
-
for such calculations?
 
-
 
-
Thanks in advance.
 
-
 
-
Massimo
 

Latest revision as of 16:26, 20 December 2005

My wiki