Acoustics in Moving Inhomogeneous Media, Second Edition

Book Preface

This book oers a complete and rigorous study of sound propagation and scattering in moving media with deterministic and random inhomogeneities in the sound speed, density, and medium velocity. This area of research is of great importance in many  elds including atmospheric and oceanic acoustics, aeroacoustics, acoustics of turbulent  ows, infrasound propagation, noise pollution in the atmosphere, theories of wave propagation, and even astrophysics, with regard to acoustic waves in extraterrestrial atmospheres. Over the past several decades, understanding of acoustics in moving media has grown rapidly, in response to its importance for practical applications such as prediction of sound propagation from highways, airports, and factories; acoustic remote sensing and tomography of the atmosphere and ocean; detection, ranging, and recognition of acoustic sources; and the study of noise emission by nozzles and exhaust pipes.

In the atmosphere, the wind velocity and its  uctuations usually lead to signicant changes in sound and infrasound propagation, such as ducting in the downwind direction and scattering into shadow zones. Strong oceanic currents and tides can a ect the phase and amplitude of acoustic signals. Sound propagation in gases or  uids are in uenced by the mean  ow. Propagation of sound waves emitted by moving sources is closely related to acoustics in moving media and is considered in this book. The bulk of the book presents systematic and rigorous formulations of sound propagation in inhomogeneous moving media, which may be applied in many areas of acoustics. Experimental data and numerical predictions considered in the book are pertinent mainly to atmospheric and oceanic acoustics. When studying outdoor sound propagation, the most advanced models for the vertical proles of temperature and wind velocity and their  uctuations in the atmospheric surface layer and for the ground impedance are used.

Contents

I Theoretical foundations of acoustics in moving media

• 1 Introduction to acoustics in a moving medium
• 2 Equations for acoustic and internal gravity waves in an inhomogeneous moving medium
• 3 Geometrical acoustics in an inhomogeneous moving medium
• 4 Wave theory of sound propagation in a stratied moving medium
• 5 Moving sound sources and receivers

II Sound propagation and scattering in random moving media

• 6 Random inhomogeneities in a moving medium and scattering
• 7 Line-of-sight sound propagation in a random moving mediumof sound
• 8 Multipath sound propagation in a random moving medium

III Numerical methods for sound propagation in moving media

• 9 Numerical representation of random elds
• 10 Ray acoustics and ground interactions
• 11 Wave-based frequency-domain methods
• 12 Wave-based time-domain methods
• 13 Uncertainty in sound propagation and its quantication