Abstract

On October 14, 1947, the sound barrier was broken by the Bell X-1, and the possibility of traveling faster than sound was proven. With the development of commercial aircraft, the TU-144 and Concorde showed that the distance between continents was not as far as people had thought. Supersonic commercial aircraft offer the possibility of significantly reduced travel time, but their wider use has been limited by sonic boom. Concorde demonstrated that traveling at Mach 2 was technically possible, but its loud far-field boom restricted its supersonic operation largely to areas above uninhabited regions such as the ocean. This essay examines how future SST aircraft may reduce sonic-boom intensity through aerodynamic and propulsion-integration design and hopefully bring continents closer again. First, the cause of sonic boom is explained through shockwave and the development of the classical N-wave. The quantification of boom intensity is then discussed in terms of peak overpressure, waveform shape, rise time, and perceived loudness level. The essay then considers possible design solutions, including fuselage shaping, wing and lift-distribution control, possible advantages brought by canards, control surfaces and engine placement. Finally, NASA’s X-59 is discussed as a modern low-boom prototype that demonstrates how aircraft shaping can transform a loud boom into a quieter sonic thump. The essay argues that future supersonic commercial aircraft must integrate low-boom design at the earliest design stage as a primary design objective, rather than treating noise as a secondary issue.