1. What is a Max Pipe Flow Calculator?

Definition: This calculator determines the volumetric flow rate of a fluid through a pipe using the Hagen-Poiseuille equation.

Purpose: It helps engineers and fluid dynamics professionals calculate the maximum laminar flow rate in cylindrical pipes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The flow rate is directly proportional to the pressure drop 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 calculations are essential for designing efficient piping systems, predicting fluid behavior, and ensuring proper system operation.

4. Using the Calculator

Tips: Enter pipe radius in meters, pressure drop in Pascals, viscosity in Pa·s (default 0.001 for water), 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 (not turbulent) flow conditions.

Q2: Why is radius to the fourth power?
A: The r⁴ relationship shows how dramatically pipe diameter affects flow rate - doubling the radius increases flow 16-fold.

Q3: What's a typical viscosity value for water?
A: Water at 20°C has viscosity of about 0.001 Pa·s, but this decreases with temperature.

Q4: How do I convert flow rate to velocity?
A: Divide flow rate (Q) by cross-sectional area (πr²) to get average velocity.

Q5: What are the limitations of this calculation?
A: It assumes steady, laminar flow of Newtonian fluids in straight, circular pipes with no-slip boundary conditions.