1. What is Pressure from Flow Rate Calculator?

Definition: This calculator determines the pressure drop in a pipe based on fluid viscosity, pipe length, flow rate, and pipe radius using the Hagen-Poiseuille equation.

Purpose: It helps engineers and fluid dynamics professionals analyze pressure losses in laminar flow systems.

2. How Does the Calculator Work?

The calculator uses the Hagen-Poiseuille equation:

Where:

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

Explanation: The equation relates pressure drop to flow characteristics in laminar flow through a cylindrical pipe.

3. Importance of Pressure Drop Calculation

Details: Accurate pressure drop calculations are essential for designing efficient piping systems, selecting appropriate pumps, and ensuring proper fluid delivery.

4. Using the Calculator

Tips: Enter the fluid viscosity, pipe length, flow rate, and pipe radius. All values must be > 0. The calculator assumes laminar flow conditions.

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).

Q2: How do I determine dynamic viscosity?
A: Dynamic viscosity values can be found in fluid property tables or measured experimentally.

Q3: Why is radius raised to the 4th power?
A: The strong dependence on radius reflects how small changes in pipe diameter significantly affect pressure drop.

Q4: Can this be used for non-circular pipes?
A: No, this equation is specifically for circular pipes. For other shapes, use the hydraulic diameter approach.

Q5: What are typical viscosity values?
A: Water at 20°C has μ ≈ 0.001 Pa·s, while honey might be ≈ 10 Pa·s.