Sökning: "acoustic wave equation"
Visar resultat 16 - 20 av 28 avhandlingar innehållade orden acoustic wave equation.
16. Rough Scatterers in Acoustics and Elastodynamics
Sammanfattning : The purpose of this thesis is to investigate the influence of roughness on wave scattering from finite-sized surfaces, in particular elastic wave scattering from cracks. Acoustic scattering from a sphere is considered using the null field approach. LÄS MER
17. The material distribution method : analysis and acoustics applications
Sammanfattning : For the purpose of numerically simulating continuum mechanical structures, different types of material may be represented by the extreme values {,1}, where 0.... LÄS MER
18. Iterative Methods for Solving the Cauchy Problem for the Helmholtz Equation
Sammanfattning : The inverse problem of reconstructing the acoustic, or electromagnetic, field from inexact measurements on a part of the boundary of a domain is important in applications, for instance for detecting the source of acoustic noise. The governing equation for the applications we consider is the Helmholtz equation. LÄS MER
19. A high-order accurate, collocated boundary element method for wave propagation in layered media
Sammanfattning : The ultimate goal of this research is to construct a hybrid model for sound propagation in layered underwater environments with curved boundaries by employing a differential formulation for inhomogeneous layers and a boundary integral formulation for homogeneous layers. The discretization of the new hybrid model is a combination of a finite difference method for the Helmholtz equation for inhomogeneous media and a collocated boundary element method (BEM) for the integral equation for homogeneous media, while taking special care of the open boundaries and the common interface. LÄS MER
20. Reliable hp finite element computations of scattering resonances in nano optics
Sammanfattning : Eigenfrequencies are commonly studied in wave propagation problems, as they are important in the analysis of closed cavities such as a microwave oven. For open systems, energy leaks into infinity and therefore scattering resonances are used instead of eigenfrequencies. LÄS MER