Development of a new, 3D, modal theory of low-frequency, long-range sound propagation through a fluctuating ocean, including both CW and transient acoustic signals. Comparison of theoretical predictions with NPAL experimental data. OBJECTIVES To develop a 3D modal theory of broadband sound propagation though a fluctuating ocean, including analysis of the coherence function for transient acousti...

We present a previously unrecognized effect of sound waves on gap-junction-based intercellular signaling such as in biological tissues composed of endothelial cells. We suggest that sound irradiation may, through temporal and spatial modulation of cell-to-cell conductance, create intercellular calcium waves with unidirectional signal propagation associated with nonconventional topologies. Nonre...

There are many approaches to determine the sound propagated from turbulent flows.  In hybrid methods, the turbulent noise source field is computed or modeled separately from the far-field calculations.  To have an initial and quick estimation of the sound propagation, less computationally intensive methods can be developed using stochastic models of the turbulent fluctuations.   In this paper, ...

The propagation of sound waves is described by partial differential equations for the acoustic pressure and the acoustic fluid velocity. The solution depends on the shape of the enclosure and on the boundary conditions. Among various methods for the discretization of partial differential equations, the multidimensional wave digital filter approach is known to yield robust algorithms for the dis...

Abstract—Fluid rheology may have essential impact on sound propagation in a liquid-filled pipe, especially, in a low frequency range. Rheological parameters of liquid are temperature-sensitive, which ultimately results in a temperature dependence of the wave speed and attenuation in the waveguide. The study is devoted to modeling of this effect at sound propagation in an elastic pipe with polym...

The exact knowledge of the sound field within an enclosure is essential for a number of applications in electro-acoustics. Conventional methods for the assessment of room acoustics model the sound propagation in analogy to the propagation of light. More advanced computational methods rely on the numerical solution of the wave equation. A recently presented method is based on multidimensional wa...

We have developed an experiment to study the propagation of laboratory synthesized fatigue cracks under various controlled conditions during Sonic IR inspection. The experiment provides for good repeatability in testing. The parameters of interest include the initial crack length, load history (stress intensity and load ratio) during crack generation, geometry of the crack, material and also th...

We describe a new nondestructive evaluation technique which makes cracks and adhesion defects visible to infrared cameras. This is accomplished by infusing the sample with a short pulse of low frequency ultrasound. The sound causes the faying surfaces of defects to heat up by friction or clapping, and thus makes them visible in the infrared. Surface or near-surface defects appear to the camera ...

Laboratory ultrasonics provides an ideal opportunity for studying wave propagation in random media. Models are relatively easy to construct and both the phase and amplitude of the wave field can be measured, so we can separate the coherent from the incoherent intensity. Here we show detailed measurements of wave propagation in a 1D strongly scattering medium that fit the theory of radiative tra...

Periodic structures composed of quarter-wavelength or Helmholtz resonators have been widely used in the design acoustic metamaterials. An interesting phenomenon achievable through hybridization such is slow sound, which results from strong dispersion produced by local resonances. It gives rise to many applications as deep subwavelength sound absorbers metadiffusers. All proposed so far analyzed...