The formula to calculate the Darcy-Weisbach friction factor (f) using the Haaland equation is:
\[ f = \left( -1.8 \log_{10} \left( \left( \frac{\epsilon}{D} \right)^{1.11} + \frac{6.9}{Re} \right) \right)^{-2} \]
Where:
The Haaland equation is an empirical formula that provides an approximation for the Darcy-Weisbach friction factor for turbulent flow in smooth and rough pipes. It is a simplified version of the more complex Colebrook-White equation and is known for its ease of use and reasonable accuracy for a wide range of conditions.
Let's assume the following values:
Using the formula:
\[ f = \left( -1.8 \log_{10} \left( \left( \frac{0.001}{3.7} \right)^{1.11} + \frac{6.9}{10000} \right) \right)^{-2} \approx 0.032 \]
The Darcy-Weisbach friction factor (f) is approximately 0.032.