Friction Loss
Friction loss, abbreviated as FL, is how much loss of flow through a pipe is due to the viscosity, the measure of the internal friction/resistance to the flow of a liquid near the surface of the pipe.
Friction loss formula |
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\(\large{ FL = f \; \frac{ l }{ d } \; \frac{ v^2 }{ 2 \; g } }\) | ||
Symbol | English | Metric |
\(\large{ FL }\) = friction loss | \(\large{ lbf }\) | \(\large{ N }\) |
\(\large{ f }\) = friction factor | \(\large{ dimensionless }\) | |
\(\large{ d }\) = inside diameter of pipe | \(\large{ in }\) | \(\large{ mm }\) |
\(\large{ l }\) = length of pipe | \(\large{ ft }\) | \(\large{ m }\) |
\(\large{ g }\) = standard gravity | \(\large{\frac{ft}{sec^2}}\) | \(\large{\frac{m}{s^2}}\) |
\(\large{ v }\) = velocity of fluid | \(\large{\frac{ft}{sec}}\) | \(\large{\frac{m}{s}}\) |
Friction loss formula |
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\(\large{ FL = C \; \left( \frac{ Q }{ 100 } \right)^2 \; \frac{ l }{ 100 } }\) | ||
Symbol | English | Metric |
\(\large{ FL }\) = friction loss | \(\large{ lbf }\) | \(\large{ N }\) |
\(\large{ Q }\) = flow rate | \(\large{\frac{ft^3}{sec}}\) | \(\large{\frac{m^3}{s}}\) |
\(\large{ C }\) = friction loss coefficient | \(\large{ dimensionless }\) | |
\(\large{ l }\) = length of pipe | \(\large{ ft }\) | \(\large{ m }\) |