Sonic Boom: From the Physics of Nonlinear Waves to Acoustic Ecology (a Review)

A history of the topic is presented. First, information is given about the development of supersonic aviation. Then, the history of studying the phenomenon of sonic boom generated by flying bullets and projectiles is briefly described. The results of the renowned aeroacoustic scientists K. Doppler and E. Mach are presented, as well as little-known historical facts found in old foreign sources. The need for correct use of the term “sonic boom” is pointed out, which is not limited to aviation acoustics problems, but is inherent to many natural and technogenic phenomena. A 100-year priority of the acoustic effect over its weaker optical counterpart, Vavilov–Cherenkov radiation, is mentioned. Problems related to calculating the generation of perturbations in the interaction of transonic and supersonic flows with real bodies are described: the need to take into account the details of the shape of the aerodynamic profile, peculiarities in the behavior of the boundary layer, the formation of shock waves, generation of flow turbulence, and the kinetics (relaxation and dissociation) of atmospheric gases. The phenomenon of wave resonance, responsible for the formation of the boom when breaking the sound barrier, is discussed. Nonlinear processes in N-wave formation in the propagation of complexly shaped signal are described. The influence of the main effects distorting the N-shaped profile is explained: diffraction, focusing, and multiple relaxation phenomena broadening the shock front. The theory of N-waves in an inhomogeneous medium is discussed. Examples of ray patterns in a standard atmosphere and in the region behind the turbulent boundary layer are constructed. Calculation methods based on nonlinear geometric acoustics and nonlinear quasioptics approximations are presented. Problems related to the consequences of sonic booms and their harmful effects on the environment, structures, and living organisms are indicated. An extensive bibliography and a list of fundamental reviews in the domestic and foreign literature are presented.