Mach Number Calculator
Calculate the Mach number and identify the flow regime.
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Enter the speed of the object and the local speed of sound (both in m/s). The calculator shows the Mach number and identifies the flow regime.
About Mach Number
The Mach number, named after Austrian physicist Ernst Mach, is a dimensionless quantity representing the ratio of flow velocity to the speed of sound. It is the key parameter in compressible fluid dynamics. At subsonic speeds (Mach less than 1), disturbances propagate ahead of the object. At supersonic speeds (Mach greater than 1), a shock wave forms. The Mach number determines aerodynamic heating, drag characteristics, and wave patterns around aircraft and projectiles.
Frequently Asked Questions
What is the Mach number?
The Mach number is the ratio of an object's speed to the local speed of sound. Mach 1 means the object travels at the speed of sound. Named after physicist Ernst Mach.
What are the flow regime classifications?
Subsonic: below Mach 0.8. Transonic: Mach 0.8 to 1.2. Supersonic: Mach 1.2 to 5. Hypersonic: above Mach 5.
Does the speed of sound change?
Yes. The speed of sound depends on temperature and medium. In air at sea level (20 C), it is about 343 m/s. It increases with temperature and is much faster in water and solids.