Search for dissertations about: "boundary-element"

Showing result 1 - 5 of 42 swedish dissertations containing the word boundary-element.

2. 1. Time Domain Boundary Element Methods for Acoustic Scattering

   Author : Georgios Natsiopoulos; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; time domain; curved surface; room acoustics; boss model; boundary element method; regularization; transient; Hermite interpolation; hypersingular; acoustic scattering; vector potential;

   Abstract : In room acoustics, numerical computation of scattering phenomena is an important subject, since it is needed to accurately predict the influence of reflectors, the audience, balconies, etc, on the perceived acoustic quality of auditoria. The large physical volumes of auditoria and the wide frequency content of music and speech, together with the complicated geometries involved however, makes predictions in room acoustics a challenging task from a computational point of view. READ MORE

4. 2. Hermitian interpolation in three-dimensional boundary element acoustics

   Author : Anders Daneryd; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : .... READ MORE

5. 3. Application of the Boundary Element Method to combustion noise and half-space problems

   Author : Haike Brick; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; impedance plane; Green s function; horn effect; Kirchhoff s surface; Hybrid approach; tyre-road interface;

   Abstract : The Boundary-Element-Method (BEM) is a powerful and established tool in computational acoustics. This thesis aims at an enhancement of the method towards combustion noise and half-space problems.First, it is directly coupled to an incompressible Large Eddy Simulation (LES) to calculate the sound radiation of open flames. READ MORE

6. 4. Fully Nonlinear Unsteady Three-Dimensional Boundary Element Method for Ship Motions in Waves

   Author : Martin Kjellberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; BEM; potential flow; MEL; ship motions; free surface; wave resistance; fully nonlinear; time-dependent;

   Abstract : The prediction of the behavior of ships in a seaway has been an important topic in ship design since the beginning of modern naval architecture. In recent years, computer simulations using numerical methods based on mathematical models of the ship hydrodynamics problem has become a valuable tool for researchers and engineers working in this field. READ MORE

7. 5. A high-order accurate, collocated boundary element method for wave propagation in layered media

   Author : Elena Sundkvist; Kurt Otto; Elisabeth Larsson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

   Abstract : 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. READ MORE