The acoustic attenuation of a single-pass, perforated concentric silencer filled with continuous strand fibers is investigated first theoretically and experimentally. The study is then extended to a specific type of hybrid silencer that consists of two single-pass perforated filling chambers combined with a Helmholtz resonator. One-dimensional analytical and three-dimensional boundary element m...

We explore the three-dimensional interaction of higher acoustic modes with bias-flow perforated liners in cylindrical and annular ducts. Pressure fluctuations in the vicinity of the liners excite the production and shedding of vorticity from the rims of apertures in the liners. An effective liner compliance is used which accounts for this transfer of acoustical into vortical energy. The investi...

We present the results of modeling of nanosecond pulse propagation in optically absorbing liquid media. Acoustic and electromagnetic wave equations must be solved simultaneously to model refractive index changes due to thermal expansion and/or electrostriction, which are highly transient phenomena on a nanosecond time scale. Although we consider situations with cylindrical symmetry and where th...

The interaction of an acoustic wave with two joined flat plates results in a diffracted acoustic wave emanating from the junction. The plates are assumed, for simplicity, to have different masses but no stiffness, and the exact solution of the two-dimensional diffraction problem is derived as a Fourier integral. The diffraction coefficient for a plane acoustic wave is found to depend in a simpl...

Several problems of current interest involve elastic bottom range-dependent ocean environments with buried or earthquake-type sources, specifically oceanic T-wave propagation studies and interface wave related analyses. Additionally, observed deep shadow-zone arrivals are not predicted by ray theoretic methods, and attempts to model them with fluid-bottom parabolic equation solutions suggest th...

In this paper, we study (3+1)-dimensional Soliton equation. We employ the Hirota’s bilinear method to obtain the bilinear form of (3+1)-dimensional Soliton equation. Then by the idea of extended three-wave method, some exact soliton solutions including breather type solutions are presented. Keywords—three-wave method; (3+1)-dimensional Soliton equation; Hirota’s bilinear form.

The coupled vibration between an acoustic field and a plate is encountered in many engineering and industrial applications. The interaction between the wind and a windshield of a car is an interesting example found in the automobile industry. Mathematically, such an interaction is described by the coupled system of the second order scalar wave equation and the fourth order plate vibration equat...

Cross-shore sediment transport is one of the effective factors in erosion and sedimentation, and affects dynamics of the beach profile in coastal areas. Furthermore, sandbar migration due to cross-shore sediment transport mostly effects beach nourishment, displacement of pollutions trapped in sediments, and organism and plants’ lives.  In this manuscript, sandbar migration due to cro...

Huygens’ principle following from the d’Alembert wave equation is not valid in two–dimensional space. A Schrödinger particle of vanishing angular momentum moving freely in two dimensions experiences an attractive force – the quantum anti–centrifugal force – towards its center. We connect these two phenomena by comparing and contrasting the radial propagators of the d’Alembert wave equation and ...