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Churchill 1977 formula

Values for calculation

$ N_{Re} $
$ ε $ $ \mathrm{m} $
$ D $ $ \mathrm{m} $
$ L $ $ \mathrm{m} $

Calculation

Friction factor

$$f=8\cdot\left[\left(\cfrac{8}{N_{Re}}\right)^{12}+\cfrac{1}{\left(\left[2.457\cdot\ln{\cfrac{1}{\left(\cfrac{7}{N_{Re}}\right)^{0.9}+\cfrac{0.27\cdot ε}{D}}}\right]^{16}+\left(\cfrac{37530}{N_{Re}}\right)^{16}\right)^{3/2}}\right]^{1/12}$$

Loss coefficient

$$ζ=f\cdot\cfrac{L}{D}$$