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 viru4u06 January 24, 2013 02:41

frictional flow

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

 viru4u06 January 24, 2013 02:49

variable friction factor

Dear all
I want to define variable friction factor across the duct.

 serene6390 February 14, 2013 18:22

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.

 viru4u06 February 15, 2013 00:42

frictional coefficient

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

Quote:
 Originally Posted by serene6390 (Post 407908) 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.

 serene6390 February 15, 2013 01:09

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?

 viru4u06 February 15, 2013 07:21

frictional coefficient

Hi, I am also looking same thing. I don't know how to define friction factor in fluent.

Quote:
 Originally Posted by serene6390 (Post 407942) 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?

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