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January 24, 2013, 02:41 
frictional flow

#1 
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virendra kumar
Join Date: Jan 2013
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Dear, I am working on frictional flow through diffuser. I have analytically derived all. I have compressible flow(air) and defined locally Reynold no. viscosity, velocity, and fanning frictional coefficient etc. at each .5mm along the diffuser. I want to define variable frictional coefficient across the diffuser. If possible please help me.
Thanks 

January 24, 2013, 02:49 
variable friction factor

#2 
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virendra kumar
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Dear all
I want to define variable friction factor across the duct. Please help me 

February 14, 2013, 18:22 

#3 
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Jing
Join Date: Feb 2013
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Hi, I wish I could answer your problem, I'm also doing frictional flow analysis with various area duct. I'm confused how did you define the frictional coefficient?
Thanks a lot! maybe we can discuss about our model later on. 

February 15, 2013, 00:42 
frictional coefficient

#4 
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virendra kumar
Join Date: Jan 2013
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By using Fanning friction factor, Darcy, and Swami Jain equation i defined the friction factor in terms of Fanning friction coefficient. i.e,
f=0.0625/(log10((K/3.7*Dh)+(5.74/Re^0.9)))^2 where K= wall roughness Dh=hydraulic dia. Re=Reynold no.=(rho*V*Dh)/mu mu= Sutherland viscosity= C1T^1.5/(T+C2) where C1=1.7165*10^5, C2= 273.11 

February 15, 2013, 01:09 

#5 
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Jing
Join Date: Feb 2013
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Thanks a lot for your explaination, but how did you set the friction factor in Fluent? I know your problem is how to set the various friction factor which unfortunately I've no idea, but I'm wondering how did you set the friction factor if it is just constant? in the wall boundary condition?


February 15, 2013, 07:21 
frictional coefficient

#6  
New Member
virendra kumar
Join Date: Jan 2013
Posts: 5
Rep Power: 5 
Hi, I am also looking same thing. I don't know how to define friction factor in fluent.
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