[viru4u06]

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]

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

[serene6390]

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]

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

Originally Posted by serene6390

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]

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]

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

Originally Posted by serene6390

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?