1. What is a Pipe Flow Calculator Pressure?

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

Purpose: It helps engineers and fluid dynamics professionals analyze pipe systems and predict flow behavior under given pressure conditions.

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 equation relates flow rate to the fourth power of pipe radius, making diameter the most significant factor in laminar flow systems.

3. Importance of Pipe Flow Calculation

Details: Accurate flow rate prediction is essential for designing efficient piping systems, ensuring proper fluid delivery, and optimizing energy consumption.

4. Using the Calculator

Tips: Enter pipe radius in meters, pressure difference in Pascals, fluid viscosity in Pa·s (default 0.001 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 is valid only for laminar flow (Re < 2100). For turbulent flow, use the Darcy-Weisbach equation.

Q2: Why is radius to the fourth power so important?
A: The flow rate is extremely sensitive to pipe diameter - doubling the radius increases flow rate by 16 times (2⁴).

Q3: What's a typical viscosity value for water?
A: Water at 20°C has a viscosity of about 0.001 Pa·s (1 centipoise). Viscosity decreases with increasing temperature.

Q4: How does pipe length affect the flow?
A: Flow rate is inversely proportional to pipe length - longer pipes have greater resistance and lower flow rates for the same pressure.

Q5: What units should I use for pressure?
A: The calculator uses Pascals (Pa). Remember that 1 bar = 100,000 Pa and 1 psi ≈ 6895 Pa.