1. What is the Gas Pipeline Pressure Drop Equation?

The Hagen-Poiseuille equation calculates pressure drop in laminar flow through a pipe. It's fundamental for designing gas pipelines and understanding fluid dynamics in cylindrical conduits.

2. How Does the Calculator Work?

The calculator uses the pressure drop equation:

Where:

• \( \Delta P \) — Pressure drop (Pa)
• \( \mu \) — Dynamic viscosity (Pa·s)
• \( L \) — Pipe length (m)
• \( Q \) — Volumetric flow rate (m³/s)
• \( D \) — Pipe diameter (m)

Explanation: The equation shows that pressure drop is directly proportional to viscosity, length, and flow rate, but inversely proportional to the fourth power of diameter.

3. Importance of Pressure Drop Calculation

Details: Calculating pressure drop is essential for pipeline design, pump sizing, and ensuring adequate flow rates in gas distribution systems.

4. Using the Calculator

Tips: Enter all values in SI units. Ensure diameter is in meters (not mm or inches) for accurate results. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What flow regimes does this equation apply to?
A: This equation is valid only for laminar flow (Re < 2100). For turbulent flow, use the Darcy-Weisbach equation.

Q2: How does pipe roughness affect the result?
A: Pipe roughness doesn't affect laminar flow calculations but is critical for turbulent flow calculations.

Q3: What's the typical viscosity range for gases?
A: Common gases at room temperature range from 0.00001 to 0.00002 Pa·s (10-20 μPa·s).

Q4: Why is diameter to the fourth power so important?
A: Small changes in diameter dramatically affect pressure drop. Doubling diameter reduces ΔP by 16 times.

Q5: Can this be used for compressible gases?
A: Only for small pressure drops where density change is negligible. For significant pressure drops, use compressible flow equations.