1. What is Gas Pressure Drop?

The pressure drop (ΔP) in a gas pipeline or conduit is the difference in pressure between two points caused by friction and other factors. It's an important parameter in fluid dynamics and engineering design.

2. How Does the Calculator Work?

The calculator uses the Hagen-Poiseuille equation for laminar flow:

Where:

• \( \Delta P \) — Pressure drop (Pa)
• \( \mu \) — Dynamic viscosity (Pa·s)
• \( L \) — Length of pipe (m)
• \( Q \) — Volumetric flow rate (m³/s)
• \( D \) — Diameter of pipe (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 designing piping systems, selecting appropriate pump sizes, and ensuring efficient operation of fluid transport systems.

4. Using the Calculator

Tips: Enter viscosity in Pa·s, length in meters, flow rate in m³/s, and diameter in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What flow regime does this equation apply to?
A: This equation is valid for laminar flow (Reynolds number < 2100). For turbulent flow, different equations like Darcy-Weisbach should be used.

Q2: What are typical viscosity values for gases?
A: Air at 20°C has viscosity of about 1.81×10⁻⁵ Pa·s. Natural gas is typically 1.1×10⁻⁵ Pa·s.

Q3: How does temperature affect pressure drop?
A: Higher temperatures generally decrease gas viscosity, which would reduce pressure drop for the same flow rate.

Q4: What if my pipe isn't circular?
A: For non-circular conduits, use the hydraulic diameter in place of D in the equation.

Q5: How accurate is this calculation?
A: It's accurate for ideal conditions (smooth pipes, fully developed flow). Real-world systems may have additional factors like fittings, bends, and roughness.