Acoustic Systems

Sound propagation involves pressures generated by elastic reaction to volumetric strain, which act to change the momentum of fluid particles, and the fluid inertia that acts on the fluid particles. These strains and pressures vary with position, so the fluid particles experience differences of pressure across them, the associated forces producing particle accelerations. Sound results from the link between accelerations and volumetric strains, both of which are functions of particle displacement (Fahy, 2001).