1. What is a Water Flow Through Pipe Calculator?

Definition: This calculator estimates the volumetric flow rate of water through a cylindrical pipe using the Hagen-Poiseuille equation.

Purpose: It helps engineers, plumbers, and fluid dynamics students determine laminar flow rates in pipe systems.

2. How Does the Calculator Work?

The calculator uses the Hagen-Poiseuille equation:

Where:

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

Explanation: The flow rate is directly proportional to the pressure difference and the fourth power of the radius, and inversely proportional to viscosity and pipe length.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation ensures proper pipe sizing, efficient system design, and meets water supply requirements.

4. Using the Calculator

Tips: Enter pipe radius (in meters), pressure difference (in Pascals), viscosity (default 0.001002 Pa·s for water at 20°C), and pipe length (in meters). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What flow regime does this equation apply to?
A: The Hagen-Poiseuille equation applies only to laminar flow (Re < 2100). For turbulent flow, use the Darcy-Weisbach equation.

Q2: What's the typical viscosity of water?
A: At 20°C, water has a viscosity of about 0.001002 Pa·s. This decreases with increasing temperature.

Q3: How does pipe radius affect flow rate?
A: Flow rate is proportional to the fourth power of radius - doubling the radius increases flow rate 16 times!

Q4: What units should I use?
A: Use consistent SI units: meters for dimensions, Pascals for pressure, and Pa·s for viscosity.

Q5: Can I use this for non-water fluids?
A: Yes, but you must input the correct viscosity value for your specific fluid.