Sonic boom, more than two centuries of investigation !

Abstract

Seventy-five years ago, Chuck Yeager on Bell-X1 broke the sound barrier. Five years later, Whitham published his seminal paper linking the shape of a supersonic body to its boom. In 1962, the French-British agreement was signed, launching the Concorde program. First flight occurred seven years later, a climax period for sonic boom research, before its current renewal following the first SSBD demonstration of in-flight boom reduction in 2003. Before this "golden-age", sonic boom, though not known under this name, was not ignored. Booms from meteoroids may have been one of the clues proving their extraterrestrial origin (Biot, 1803) following the hypothesis of Chladni (1794). Infrasound of great Siberian meteorite was recorded in 1908. Shock from the tip of a cracking-whip, the oldest human-made supersonic object, was visualised by Carrière's schlieren shadow photographies in 1927. This method was already used by Mach in 1887, exhibiting the conical shockfront produced by a bullet, now bearing his name but earlier conceptualised by Doppler. During World War One, trying to localise acoustically artillery guns, Esclangon established the modern ray-tracing equations launched from the Mach cone of a supersonic gun shell. The paper will briefly discuss these early works and some others.