Search for dissertations about: "Boundary Element Method"

Showing result 6 - 10 of 187 swedish dissertations containing the words Boundary Element Method.

  2. 6. Adaptive Finite Element Methods for Optimal Control Problems

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

    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

  4. 7. On adaptive finite element methods based on a posteriori estimates

    Author : Axel Målqvist; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite element method; Galerkin; duality; a posteriori error estimation; adaptivity; Poisson equation; boundary penalty method; Helmholtz equation; pollution; variational multiscale method; adaptivity;

    Abstract : .... READ MORE

  5. 8. A hybrid finite element method for electromagnetics with applications in time-domain

    Author : DAVID DEGERFELDT; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nitsche s method; antenna arrays; NASA almond; edge elements; scattering; explicit-implicit time-stepping; Maxwell s equations; Finite Element Method; mass lumping; stability analysis; Finite-Differences Time-Domain; periodic structures; shape and material optimization;

    Abstract : In this thesis, a new hybrid method that combines the Finite Element Method (FEM) with the Finite-Difference in Time-Domain (FDTD) method is presented. Tetrahedrons in the unstructured FEM region are connected directly to thehexahedrons in the structured FDTD region. READ MORE

  6. 9. Aspects of adaptive mesh refinement in the spectral element method

    Author : Nicolas Offermans; Philipp Schlatter; Ananias Tomboulides; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Error estimators; mesh refinement; adaptivity; spectral element method; algebraic multigrid method; NACA4412; periodic hill case.; Engineering Mechanics; Teknisk mekanik;

    Abstract : This thesis deals with the improvement of the efficiency of numerical simulations in computational fluid dynamics. Some of the limitations of current algorithms on future exascale supercomputers are addressed with the main goal of using adaptive mesh refinement for the simulation of turbulent and three-dimensional flows. READ MORE

  7. 10. On the modelling of ultrasonic testing using boundary integral equation methods

    Author : Jonathan Westlund; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Boundary element method; Regularization; Ultrasonics; Boundary integral equation method; T matrix.; Elastic waves; Nondestructive testing; Scattering;

    Abstract : Ultrasonic nondestructive testing has important applications in, for example, the nuclearpower and aerospace industries, where it is used to inspect safety-critical parts for flaws.For safe and reliable testing, mathematical models of the ultrasonic measurement systemsare invaluable tools. READ MORE