1. What is the Mach Number?

The Mach number is a dimensionless quantity representing the ratio of flow velocity past a boundary to the local speed of sound. It's a fundamental parameter in aerodynamics and fluid dynamics.

2. How Does the Calculator Work?

The calculator uses the Mach number equation:

Where:

• \( M \) — Mach number (dimensionless)
• \( v \) — Velocity of the object (m/s)
• \( \gamma \) — Specific heat ratio (dimensionless)
• \( R \) — Specific gas constant (J/kg·K)
• \( T \) — Temperature of the fluid (K)

Explanation: The equation calculates how many times faster the object is moving compared to the speed of sound in that medium.

3. Importance of Mach Number

Details: Mach number is crucial in aerodynamics for classifying flow regimes (subsonic, transonic, supersonic, hypersonic) and predicting compressibility effects.

4. Using the Calculator

Tips: Enter velocity in m/s, specific heat ratio (1.4 for air), gas constant (287 J/kg·K for air), and temperature in Kelvin. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What does Mach 1 mean?
A: Mach 1 means the object is moving at exactly the speed of sound in that medium (about 343 m/s in air at 20°C).

Q2: What are typical Mach number ranges?
A: Below 0.8 (subsonic), 0.8-1.2 (transonic), 1.2-5.0 (supersonic), above 5.0 (hypersonic).

Q3: Why does temperature affect Mach number?
A: The speed of sound increases with temperature, so the same velocity corresponds to a lower Mach number at higher temperatures.

Q4: What's the typical γ value for air?
A: For dry air at standard conditions, γ is approximately 1.4.

Q5: Can this be used for any gas?
A: Yes, but you need to use the appropriate γ and R values for the specific gas.