corneliusd
Chemical
- Jun 19, 2016
- 9
Good morning,
I have been reading the equations provided by Darby (Chemical Engineering Fluid Mechanics 2nd Ed) to estimate the friction factor for Bingham plastics in both laminar and turbulent flow.
The generalized method suggests a combination of the laminar and turbulent friction factor as follows:
f = (fl^m + ft^m)^(1/m)
m = 1.7 + 40,000/Re
However, I noticed that when using this equation I get different results than using just the laminar or turbulent equivalent, and more over, the resulting f is bigger than both laminar and turbulent.
I am wondering if there is any update to this expression in further editions, or if there is something I am missing.
Thanks a lot,
CD
I have been reading the equations provided by Darby (Chemical Engineering Fluid Mechanics 2nd Ed) to estimate the friction factor for Bingham plastics in both laminar and turbulent flow.
The generalized method suggests a combination of the laminar and turbulent friction factor as follows:
f = (fl^m + ft^m)^(1/m)
m = 1.7 + 40,000/Re
However, I noticed that when using this equation I get different results than using just the laminar or turbulent equivalent, and more over, the resulting f is bigger than both laminar and turbulent.
I am wondering if there is any update to this expression in further editions, or if there is something I am missing.
Thanks a lot,
CD