The advent of metamaterials in acoustics is shaking-up the research community. The theoretical models and the realization technologies developed during the last decade have suddenly made possible applications that were barely conceivable before. Acoustic invisibility, perfect acoustic mirrors and lenses or ideal wave guides are now realizable with devices exploiting the potential of acoustic me...

The interaction of acoustic waves with fluid-loaded shell structures is an ongoing area of interest in underwater acoustics, ship construction and detection. The elasticity of the structure permits strong surfaceborne wave effects, which can be significant or dominant in large structures (many wavelengths in size). The significance of surface borne waves is compounded by low loss factors, enabl...

We have developed a technique in ultrasonic correlation spectroscopy called diffusing acoustic wave spectroscopy (DAWS). In this technique, the motion of the scatterers (e.g., particles or inclusions) is determined from the temporal fluctuations of multiply scattered sound. In DAWS, the propagation of multiply scattered sound is described using the diffusion approximation, which allows the auto...

The idea of using acoustically induced Doppler spectra as a means for target detection and identification is introduced. An analytical solution for the calculation of the bistatic scattered Doppler spectrum from an acoustically excited, vibrating metallic circular cylinder is presented. First the electromagnetic scattering solution of a slightly deformed circular cylinder is obtained using a pe...

We analyze and interpret resonant Raman-Brillouin scattering by folded acoustic vibrations in short-period GaAs/AlAs superlattices. Analysis of the spectra and their resonance behavior is performed using a RamanBrillouin electronic density constructed by combining thousands transitions between electronic eigenstates of the system according to their weight in the light-scattering process. We sho...

S (in alphabetic order by speaker surname) Speaker: Nathan Albin (Kansas State University) Title: Fourier Continuation Methods for Long-Range Propagation and Transport Abstract: The Fourier Continuation (FC) method is a numerical technique for expressing nonperiodic functions as restrictions of rapidly converging Fourier series, thus avoiding the Gibbs phenomenon and enabling the use of Fourier...

Three–wave nonlinear resonant interaction (TWRI) is typically encountered in the description of any conservative nonlinear medium where the nonlinear dynamics can be considered as a perturbation of the linear wave solution, the lowest–order nonlinearity is quadratic in the field amplitudes, the three–wave resonance can be satisfied [1]. Indeed TWRI is the lowest–order nonlinear effect for a sys...

The suspended sediment layer occupies the lower water column. Presence of the suspended sediments creates a volume scattering layer which affects acoustic detection. Understanding the acoustic effects of the suspended sediment layer leads to the development of acoustic sensors with capability to scan the seafloor and to detect ordnance such as sea mines. 2. Comprehensive Acoustic Simulation Sys...

Kussmaul's (1969) formulation of acoustic scattering problems involves the superposition of a double-layer distribution and a simple-layer distribution on the boundary.This ensured the existence of a unique solution for all wave numbers of the incoming wave. However,the boundary integral equation involves a highly singular kernel which proves difficult to treat numerically. An alternative appro...

it is well established that the seismic ground response of surface topographies may differ from those of free field motion during earthquakes. complex nature of seismic wave scattering by topographical structures can only be solved accurately and economically using advanced numerical methods under realistic conditions. among the numerical methods, the boundary element is a powerful numerical te...