When a plane breaks the speed of sound, it creates a phenomenon known as a sonic boom and generates shock waves.
Breaking the sound barrier is a dramatic event in aviation. Here's a breakdown of what occurs:
The Sonic Boom Explained
- As an aircraft approaches the speed of sound (approximately 767 mph or Mach 1 at sea level), the air in front of it cannot move out of the way quickly enough.
- This results in the air being compressed, forming shock waves.
- When the aircraft exceeds Mach 1, it is continually generating these shock waves.
- These shock waves propagate outward and downward from the aircraft.
- When these shock waves reach the ground, they are heard as a loud boom, which is the sonic boom.
- According to the reference, "As an aircraft flies at supersonic speeds it is continually generating shock waves, dropping sonic boom along its flight path...".
- The sonic boom is not a one-time event; the aircraft is, according to the reference, "...similar to someone dropping objects from a moving vehicle" which means that the boom will continue to be swept backwards along the flight path as the aircraft travels away.
Effects of Breaking the Sound Barrier
- Audible Noise: The most noticeable effect is the loud sonic boom.
- Pressure Changes: Rapid pressure changes can sometimes cause minor structural damage to buildings, such as cracked windows. This is typically only a concern with very large aircraft flying at low altitudes.
- Aerodynamic Changes: The aircraft experiences significant changes in aerodynamic forces, requiring careful design and control systems.
Visual Observations
- Vapor Cone (Prandtl-Glauert Singularity): Under certain atmospheric conditions, a visible cloud of condensed water vapor may briefly form around the aircraft. This is not directly related to breaking the sound barrier but rather to the rapid pressure drop around the aircraft. It's an interesting visual phenomenon, though!
