Haaland Equation Calculator

Calculate Friction Factor using Haaland Equation



Formula

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:

What is the Haaland Equation?

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.

Example Calculation

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.