Friction Factor Calculator

Formula Used:

\[ f = \frac{64 \times \mu}{\rho_{Fluid} \times V_{mean} \times D_{pipe}} \]

Dynamic Viscosity (μ):

Pa·s

Density of Fluid (ρ):

kg/m³

Mean Velocity (V):

m/s

Diameter of Pipe (D):

Darcy Friction Factor (f):

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1. What is the Darcy Friction Factor?

The Darcy Friction Factor is a dimensionless quantity used in fluid mechanics to characterize the frictional losses in pipe flow. Its value depends on the flow's Reynolds number and the pipe's relative roughness, and it can be obtained from Moody's chart for turbulent flow conditions.

2. How Does the Calculator Work?

The calculator uses the formula for laminar flow:

\[ f = \frac{64 \times \mu}{\rho_{Fluid} \times V_{mean} \times D_{pipe}} \]

Where:

\( f \) — Darcy Friction Factor (dimensionless)
\( \mu \) — Dynamic Viscosity (Pa·s)
\( \rho_{Fluid} \) — Density of Fluid (kg/m³)
\( V_{mean} \) — Mean Velocity (m/s)
\( D_{pipe} \) — Diameter of Pipe (m)

Explanation: This formula applies specifically to laminar flow conditions (Re < 2300) where the friction factor is inversely proportional to the Reynolds number.

3. Importance of Friction Factor Calculation

Details: Accurate calculation of the friction factor is crucial for determining pressure drops in piping systems, designing efficient fluid transport systems, and calculating energy losses in fluid flow applications.

4. Using the Calculator

Tips: Enter dynamic viscosity in Pa·s, density in kg/m³, mean velocity in m/s, and diameter in meters. All values must be positive and non-zero. This calculator is valid for laminar flow conditions only.

5. Frequently Asked Questions (FAQ)

Q1: When is this formula applicable?
A: This formula is specifically for laminar flow conditions where the Reynolds number is less than 2300.

Q2: What about turbulent flow?
A: For turbulent flow, the friction factor depends on both Reynolds number and pipe roughness, and is typically determined using the Moody chart or Colebrook equation.

Q3: What are typical values for the Darcy friction factor?
A: For laminar flow, f = 64/Re. For turbulent flow in smooth pipes, f typically ranges from 0.008 to 0.08 depending on Reynolds number.

Q4: How does pipe roughness affect the friction factor?
A: In turbulent flow, increased pipe roughness leads to higher friction factors. In laminar flow, pipe roughness has negligible effect.

Q5: What are the units for the friction factor?
A: The Darcy friction factor is a dimensionless quantity with no units.