Darcy Friction Factor - Brkić formula |
||
| \( \dfrac{ 1 }{ \sqrt{f_d} } \;=\; -2 \cdot log_{10} \cdot \left( \dfrac{ \dfrac{ \epsilon }{ d } }{ 3.71} + \dfrac{ 2.18 \cdot n }{ Re } \right) \) | ||
| Symbol | English | Metric |
| \( f_d \) = Darcy Friction Factor | \( dimensionless \) | \( dimensionless \) |
| \( ln \) = Natural Logarithm | \( dimensionless \) | \( dimensionless \) |
| \( \epsilon \) (Greek symbol epsilon) = Pipe's Effective Roughness Height | \( in \) | \( mm \) |
| \( d \) = Pipe Inside Diameter | \( in \) | \( mm \) |
| \( Re \) = Reynolds Number | \( dimensionless \) | \( dimensionless \) |
| \( n \) = Variable in Brkić | \( dimensionless \) | \( dimensionless \) |
Darcy friction factor – Brkić is an empirical correlation created by Dejan Brkić as an alternative method for estimating the Darcy friction factor, a dimensionless number, used to quantify the resistance or energy loss due to friction in pipe flow. Traditional approaches, such as the Colebrook–White equation, are implicit and require iterative solutions, which can be computationally intensive.
Brkić proposed explicit approximations that simplify the calculation of the Darcy friction factor while maintaining accuracy across both laminar and turbulent flow regimes. His formulations are widely recognized for providing reliable, closed-form expressions that eliminate the need for iterative procedures, making them especially useful in engineering applications where quick and efficient calculations of head loss, pressure drop, or flow behavior in pipelines are required.
