1. What is the Darcy Friction Factor?

The Darcy friction factor (f) is a dimensionless quantity used in the Darcy-Weisbach equation to calculate pressure loss due to friction in pipes. For laminar flow (Re < 2300), it can be calculated directly from the Reynolds number.

2. How Does the Calculator Work?

The calculator uses the laminar flow equation:

Where:

• \( f \) — Darcy friction factor (dimensionless)
• \( Re \) — Reynolds number (dimensionless)

Explanation: This equation applies only to laminar flow conditions (Re < 2300). For turbulent flow, more complex equations or the Moody chart are needed.

3. Importance of Friction Factor Calculation

Details: The friction factor is essential for calculating pressure drops in piping systems, which affects pump sizing and system design in chemical, civil, and mechanical engineering applications.

4. Using the Calculator

Tips: Enter the Reynolds number (must be > 0). The calculator is valid only for laminar flow conditions (Re < 2300).

5. Frequently Asked Questions (FAQ)

Q1: What is laminar flow?
A: Laminar flow occurs at low Reynolds numbers (Re < 2300) where fluid flows in parallel layers with no disruption between them.

Q2: How is Reynolds number calculated?
A: \( Re = \frac{\rho v D}{\mu} \), where ρ is density, v is velocity, D is diameter, and μ is dynamic viscosity.

Q3: What about turbulent flow?
A: For turbulent flow (Re > 4000), the Colebrook equation or Moody chart should be used to find the friction factor.

Q4: What are typical friction factor values?
A: For laminar flow, f ranges from ~0.01 to 0.1. For turbulent flow in smooth pipes, f is typically 0.02-0.04.

Q5: What are the limitations of this equation?
A: Only valid for laminar flow in circular pipes. Doesn't account for pipe roughness or transitional flow regimes.