1. What is Mass Flow Rate in Thermodynamics?

Definition: Mass flow rate is the amount of mass passing through a given surface per unit time in thermodynamic systems.

Purpose: It's crucial for designing and analyzing fluid systems, heat exchangers, and various thermodynamic processes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( W \) — Mass flow rate (lb/hr)
• \( Q \) — Volumetric flow rate (gallons per minute, GPM)
• \( \rho \) — Density of the fluid (pounds per gallon, lb/gal)
• 60 — Conversion factor (minutes to hours)

Explanation: The volumetric flow rate is converted to mass flow rate by multiplying by density and converting the time unit.

3. Importance of Mass Flow Rate Calculation

Details: Accurate mass flow rate calculations are essential for system design, energy balance calculations, and equipment sizing in thermodynamic systems.

4. Using the Calculator

Tips: Enter the volumetric flow rate in GPM and fluid density in lb/gal (default 8.34 for water at 60°F). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 60 used?
A: It converts minutes (from GPM) to hours (for lb/hr), as mass flow rate is typically expressed per hour.

Q2: What's a typical density for water?
A: Water at 60°F has a density of about 8.34 lb/gal, but this varies with temperature.

Q3: Can I use this for gases?
A: This formula works best for liquids. For gases, you'd need to account for compressibility and use different units.

Q4: How do I find volumetric flow rate?
A: Use flow meters or calculate from pipe diameter and velocity (Q = A × v).

Q5: What if my density is in different units?
A: Convert to lb/gal first (1 lb/gal = 119.826 kg/m³ = 0.1198 g/cm³).