Search for dissertations about: "spectral element"

Showing result 1 - 5 of 98 swedish dissertations containing the words spectral element.

  2. 1. Spectral-element simulations of separated turbulent internal flows

    Author : Johan Ohlsson; Dan Prof Henningson; Jesper Oppelstrup; KTH; []
    Keywords : spectral element method; direct numerical simulations DNS ; turbulence; dealiasing; three-dimensional separation; massively parallel simulations;

    Abstract : .... READ MORE

  4. 2. Prediction of random vibration using spectral methods

    Author : Fredrik Birgersson; KTH; []
    Keywords : Spectral finite element method; distributed excitation; turbulent boundary layer measurements; random vibration; spectral super element method; wave expansion difference scheme; fluid-structure interaction;

    Abstract : Much of the vibration in fast moving vehicles is caused bydistributed random excitation, such as turbulent flow and roadroughness. Piping systems transporting fast flowing fluid isanother example, where distributed random excitation will causeunwanted vibration. READ MORE

  5. 3. 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

  6. 4. Efficient Solvers for Space-Time Discontinuous Galerkin Spectral Element Methods

    Author : Lea Miko Versbach; Numerisk analys; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Discontinuous Galerkin Method; Spectral Element Method; Finite Volume Method; Implicit Schemes; Preconditioner; Multigrid Method; Space-Time; Lobatto IIIC Method; Local Fourier Analysis;

    Abstract : In this thesis we study efficient solvers for space-time discontinuous Galerkin spectral element methods (DG-SEM). These discretizations result in fully implicit schemes of variable order in both spatial and temporal directions. READ MORE

  7. 5. Spectral-element simulations of turbulent wall-bounded flows including transition and separation

    Author : Johan Malm; Dan Henningson; Philipp Schlatter; Suad Jakirlic; KTH; []
    Keywords : spectral-element method; direct numerical simulation DNS ; large-eddy simulation LES ; turbulence; transition; over-integration; three-dimensional separation; massively parallel simulations; proper orthogonal decomposition POD ; Koopman modes; vorticity stretching; coherence; SRA - E-vetenskap SeRC ; SRA - E-Science SeRC ;

    Abstract : The spectral-element method (SEM) is used to study wall-bounded turbulent flowsin moderately complex geometries. The first part of the thesis is devoted to simulations of canonical flow cases, such as temporal K-type transitionand turbulent channel flow, to investigate general resolution requirements and computational efficiency of the numerical code nek5000. READ MORE