1. What is Volume Flow Rate?

Definition: Volume flow rate is the volume of fluid that passes through a given surface per unit time.

Purpose: This calculator helps determine the flow rate in gallons per minute (GPM) based on fluid velocity and cross-sectional area.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Volume flow rate (gallons per minute, GPM)
• \( V \) — Velocity of the fluid (feet per second, ft/s)
• \( A \) — Cross-sectional area (square feet, ft²)
• 448.83 — Conversion factor (1 ft³/s = 448.83 GPM)

Explanation: The formula calculates how many gallons pass through a given area each minute based on the fluid's velocity.

3. Importance of Volume Flow Rate Calculation

Details: Accurate flow rate calculations are essential for designing piping systems, irrigation systems, and hydraulic machinery.

4. Using the Calculator

Tips: Enter the fluid velocity in ft/s and the cross-sectional area in ft². All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 448.83?
A: This converts cubic feet per second to gallons per minute (1 ft³ = 7.48052 gallons, 1 minute = 60 seconds).

Q2: How do I measure cross-sectional area?
A: For pipes, use \( A = \pi r² \) where r is the radius. For rectangular ducts, use width × height.

Q3: What's a typical velocity for water in pipes?
A: Residential plumbing typically uses 4-8 ft/s, while industrial systems may use higher velocities.

Q4: Can this be used for gases?
A: Yes, but gas flow calculations often require additional factors like compressibility and temperature.

Q5: How accurate is this calculation?
A: It provides theoretical maximum flow; actual flow may be less due to friction, viscosity, and other factors.