Formula Pressure Drop

Pressure Drop Formula:

\[ \Delta P = f \left( \frac{L}{D} \right) \left( \frac{\rho v^2}{2} \right) \]

Friction Factor (f):

dimensionless

Pipe Length (L):

meters

Pipe Diameter (D):

meters

Fluid Density (ρ):

kg/m³

Flow Velocity (v):

m/s

Pressure Drop (ΔP): Pa

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1. What is the Pressure Drop Formula?

Definition: This calculator computes the pressure drop in a pipe due to friction using the Darcy-Weisbach equation.

Purpose: It helps engineers and fluid system designers determine the pressure loss in piping systems.

2. How Does the Calculator Work?

The calculator uses the Darcy-Weisbach equation:

\[ \Delta P = f \left( \frac{L}{D} \right) \left( \frac{\rho v^2}{2} \right) \]

Where:

\( \Delta P \) — Pressure drop (Pascals)
\( f \) — Darcy friction factor (dimensionless)
\( L \) — Pipe length (meters)
\( D \) — Pipe diameter (meters)
\( \rho \) — Fluid density (kg/m³)
\( v \) — Flow velocity (m/s)

Explanation: The formula calculates the pressure loss due to friction between the fluid and the pipe walls.

3. Importance of Pressure Drop Calculation

Details: Accurate pressure drop calculations are essential for proper pump sizing, system design, and ensuring adequate flow rates in piping systems.

4. Using the Calculator

Tips: Enter the friction factor (typically 0.01-0.05 for turbulent flow), pipe dimensions, fluid properties, and flow velocity. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine the friction factor?
A: The friction factor depends on the Reynolds number and pipe roughness. Use Moody charts or empirical formulas.

Q2: What units should I use?
A: The calculator uses SI units: meters for length, kg/m³ for density, m/s for velocity, and outputs Pascals.

Q3: Does this account for fittings and valves?
A: No, this calculates straight pipe losses only. Use equivalent length methods for fittings.

Q4: What's a typical friction factor?
A: For turbulent flow in smooth pipes, 0.01-0.02; for rough pipes, 0.03-0.05.

Q5: Can I use this for gases?
A: Yes, but for compressible fluids, additional considerations are needed for accurate results.