Subsonique

Subsonique refers to speeds that are slower than the speed of sound. The speed of sound varies depending on the medium through which it travels, but in dry air at 20 degrees Celsius (68 degrees Fahrenheit), it is approximately 343 meters per second or 767 miles per hour. An object or phenomenon traveling at subsonique speeds is moving at a rate less than this threshold.

This designation is commonly used in the fields of aerodynamics and acoustics. Aircraft that fly at speeds below the speed of sound are classified as subsonique aircraft. Most commercial airliners operate within the subsonique range. In contrast, supersonic speeds are faster than the speed of sound, and transsonique speeds are those close to the speed of sound, where aerodynamic effects can become complex.

The concept of subsonique is fundamental to understanding fluid dynamics and the behavior of objects moving through air or other fluids. When an object travels at subsonique speeds, the air molecules in front of it have sufficient time to move out of the way, and the air flows smoothly around the object. This contrasts with supersonic flight, where the object outruns the pressure waves it creates, leading to shock waves and a sonic boom.