Search for dissertations about: "Boundary Element Method"

Showing result 1 - 5 of 144 swedish dissertations containing the words Boundary Element Method.

  1. 1. The material distribution method analysis and acoustics applications

    University dissertation from Umeå : Umeå Universitet

    Author : Fotios Kasolis; Umeå universitet.; [2014]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material distribution method; fictitious domain method; finite element method; Helmholtz equation; linear elasticity; shape optimization; topology optimization;

    Abstract : For the purpose of numerically simulating continuum mechanical structures, different types of material may be represented by the extreme values {,1}, where 0<1, of a varying coefficient  in the governing equations. The paramter  is not allowed to vanish in order for the equations to be solvable, which means that the exact conditions are approximated. READ MORE

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

    University dissertation from Umeå : Umeå Universitet

    Author : Georgios Natsiopoulos; [2008]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hypersingular; time domain; room acoustics; acoustic scattering; regularization; vector potential; transient; curved surface; boundary element method; boss model; Hermite interpolation;

    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

  3. 3. Simulation of individual cells in flow

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Lailai Zhu; KTH.; [2014]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrodynamic interaction; swimming microorganisms; capsule; Stokes flow; finite element method; boundary integral method; general geometry Ewald method; spectral element method; viscoelastic fluid; cellular deformation; flow cytometry; cell sorting; microrheology; Teknisk mekanik; Engineering Mechanics;

    Abstract : In this thesis, simulations are performed to study the motion ofindividual cells in flow, focusing on the hydrodynamics of actively swimming cells likethe self-propelling microorganisms, and of passively advected objects like the red bloodcells. In particular, we develop numerical tools to address the locomotion ofmicroswimmers in viscoelastic fluids and complex geometries, as well as the motion ofdeformable capsules in micro-fluidic flows. READ MORE

  4. 4. Shape Optimization for Acoustic Wave Propagation Problems

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Rajitha Udawalpola; Uppsala universitet.; Uppsala universitet.; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; shape optimization; design optimization; acoustic wave propagation; Helmholtz equation; Boundary Element Method; Finite Element Method; inverse problems; adjoint method; gradient-based optimization; Scientific Computing; Beräkningsvetenskap;

    Abstract : Boundary shape optimization is a technique to search for an optimal shape by modifying the boundary of a device with a pre-specified topology. We consider boundary shape optimization of acoustic horns in loudspeakers and brass wind instruments. READ MORE

  5. 5. Adaptive Finite Element Methods for Optimal Control Problems

    University dissertation from Göteborg : Chalmers University of Technology

    Author : Karin Kraft; Göteborgs universitet.; Gothenburg University.; [2011]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite element method; discontinuous Galerkin method; optimal control; a posteriori error estimate; dual weighted residual; adaptive; multilevel algorithm; Newton method; control constraint; variational inequality; vehicle dynamics.;

    Abstract : In this thesis we study the numerical solution of optimal control problems. The problems considered consist of a systemof differential equations, the state equations, which are governed bya control variable. The goal is to determine the states and controls which minimize a given cost functional. READ MORE