Sökning: "Inhomogeneous Wave Equation"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Inhomogeneous Wave Equation.

1. 1. Scattering on the Timoshenko Beam. Direct and Inverse Problems in the Time Domain

   Författare :Dag V. J. Billger; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; integro-differential equations; wave splitting; transient wave propagation; viscoelastic damping; wave propagators; inverse problems; scattering operators; Timoshenko beam; non-uniform beams; imbedding;

   Sammanfattning : This thesis concerns the use of time domain methods for treating direct and inverse scattering problems for flexural waves on beams. The Timoshenko equation is used throughout to describe the behaviour of such waves. LÄS MER

3. 2. Computational Aeroacoustics Based on Large Eddy Simulation and Acoustic Analogies

   Författare :Mihai Mihaescu; Laszlo Fuchs; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical engineering; hydraulics; plasma; Technological sciences; Teknik; fluiddynamik; plasmas; Gaser; fluid dynamics; Gases; Inhomogeneous Wave Equation; Acoustic Boundary Conditions; Acoustic Source Terms; LES; Computational Aeroacoustics; Turbulent Flows; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Computational Aeroacoustics;

   Sammanfattning : The thesis presents a numerical method developed by the author and its applications for computing the generated sound by an unsteady flow field and its propagation. The full equations of motion for compressible and unsteady flows describe both flow field and sound generation and propagation. LÄS MER

4. 3. Topics in Simulation and Stochastic Analysis

   Författare :Mikael Signahl; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik; stochastic heat equation; stochastic wave equation; error rates; truncated Levy process; discontinuities; optimal decay rate; digital communication system;

   Sammanfattning : Paper A investigates how to simulate a differentiated mean in cases where interchanging differentiation and expectation is not allowed. Three approaches are available, finite differences (FD's), infinitesimal perturbation analysis (IPA) and the likelihood ratio score function (LRSF) method. LÄS MER

5. 4. Transient waves in nonstationary media : with applications to lightning and nonlinear media

   Författare :Ingegerd Åberg; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lightning; Klein-Gordon; nonlinear; characteristics; wave splitting; imbedding; sources; propagators; Green functions; direct and inverse scattering; Nonstationary; transient; high-frequency switching; Kerr.; Technological sciences; Teknik;

   Sammanfattning : Propagation of transient waves in nonstationary, inhomogeneous, dispersive, stratified media is considered. Waves originating from sources exterior to the scatterer as well as from internal sources are treated. Algorithms are developed and illustrated by computations of wave phenomena in stationary, nonstationary and weakly nonlinear media. LÄS MER

7. 5. Applications of 3D time domain wave splittings to direct and inverse scattering

   Författare :Jiasu Cao; KTH; []
   Nyckelord :;

   Sammanfattning : The three-dimensional direct and inverse scattering problems in the time-domain are considered in the present thesis. The direct problem is to find an explicit or numerical solution of the transient reflection for given physical parameters. LÄS MER