Supersonic speed

Supersonic speed is the rate of travel of an object that exceeds the speed of sound (Mach 1). For objects traveling in dry air at a temperature of 20 °C (68 °F), this speed is approximately 343 meters per second (1,235 km/h; 767 mph). Speeds greater than Mach 1 are considered supersonic, while speeds greater than Mach 5 are classified as hypersonic. The term "supersonic" is used primarily to describe the speeds of aircraft, missiles, and bullets, but can also apply to any object that moves faster than sound, such as certain spacecraft.

Overview

When an object moves through the air at a speed faster than sound, it generates a shock wave of compressed air molecules. This shock wave, when reaching an observer, is heard as a sonic boom. The study of supersonic and hypersonic speeds is part of the field of aerodynamics, which is a sub-discipline of fluid dynamics. The behavior of air and other gases changes significantly at supersonic speeds, leading to unique challenges in the design and control of supersonic vehicles.

History

The quest to achieve supersonic speed began in the early 20th century. The first recorded instance of an object reaching supersonic speed was during World War II, with the development of the V-2 rocket by Germany. However, the first manned supersonic flight was achieved by Chuck Yeager in the Bell X-1 aircraft in 1947. Since then, numerous aircraft, both military and civilian, have been designed to operate at supersonic speeds.

Physics of Supersonic Flight

At supersonic speeds, the air flow around an object experiences significant changes. The air cannot "get out of the way" quickly enough, leading to the formation of shock waves. These shock waves are responsible for the sonic boom associated with supersonic flight. Additionally, the pressure, temperature, and density of the air change across the shock wave, which can affect the aerodynamics of the vehicle.

The design of supersonic aircraft often involves a delta wing or swept wing configuration to manage these effects. Moreover, the phenomenon of wave drag becomes a critical factor at supersonic speeds, necessitating careful consideration in the design of the aircraft's shape.

Applications

Supersonic speeds have primarily been exploited in military applications, including fighter jets and missiles. The ability to move faster than sound provides significant tactical advantages in combat. In the civilian sector, the most notable example of supersonic travel was the Concorde, a passenger airliner that operated at speeds up to Mach 2.04. However, issues such as high operational costs, environmental concerns, and the sonic boom led to the retirement of the Concorde in 2003.

Future of Supersonic Travel

Recent advancements in technology have led to renewed interest in supersonic travel, with several companies working on developing new supersonic passenger aircraft. These efforts aim to overcome the challenges of noise, efficiency, and cost that plagued earlier supersonic aircraft. Additionally, research into scramjet engines could enable hypersonic flight, significantly reducing travel times for long-distance trips.

See Also

• Mach number
• Transonic speed
• Sound barrier
• Aerodynamics