ṁ: This symbol represents the mass flow rate, which is the amount of mass passing through a given cross-sectional area per unit time. It’s typically measured in kilograms per second (kg/s) or other mass/time units.
- ṁ: Mass flow rate (kg/s)
- 𝜌*: Density of the fluid (kg/m³)
- u: Velocity (speed of sound) (m/s)
- A*: Cross-sectional area (m²)