@wikipedia
Quantitative dimensionless measure
of the friction forces between fluid pipe flow and inner pipe walls based on Darcy–Weisbach equation.It depends on Reynolds number and inner pipe walls roughness (see Fig. 1): LaTeX Math Inline |
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body | --uriencoded--f =f(%7B\rm Re%7D, \, \epsilon) |
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In engineering practice one can use either Moody Chart or Darcy friction factor @model to estimate the actual value of Darcy friction factor.
Darcy friction factor
takes only positive values but has singularity at zero flow velocity: LaTeX Math Inline |
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body | --uriencoded--%7B\rm Re%7D \rightarrow 0 \Rightarrow f \rightarrow \infty |
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which may cause computational challenges.Using Reduced Friction Factor
LaTeX Math Inline |
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body | --uriencoded--\Phi = f \cdot %7B\rm Re%7D / 64 |
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instead can help in computations as it stays finite for all finite values of Reynolds number . See also
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Physics / Fluid Dynamics / Pipe Flow Dynamics / Darcy–Weisbach equation
[ Darcy friction factor Single-phase @model ] [ Reynolds Number for Multiphase Flow @model ]
[ Moody Chart ] [ Fluid flow regimes ]Reduced Friction Factor (Φ) ]