Search for dissertations about: "periodic boundary condition"

Showing result 16 - 20 of 22 swedish dissertations containing the words periodic boundary condition.

  2. 16. High-Performance Finite Element Methods : with Application to Simulation of Diffusion MRI and Vertical Axis Wind Turbines

    Author : Van-Dang Nguyen; Johan Hoffman; Johan Jansson; Axel Målqvist; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; High performance finite element method; computational diffusion MRI; turbulent flow; vertical axis wind turbine.; Computer Science; Datalogi;

    Abstract : The finite element methods (FEM) have been developed over decades, and together with the growth of computer engineering, they become more and more important in solving large-scale problems in science and industry. The objective of this thesis is to develop high-performance finite element methods (HP-FEM), with two main applications in mind: computational diffusion magnetic resonance imaging (MRI), and simulation of the turbulent flow past a vertical axis wind turbine (VAWT). READ MORE

  4. 17. Optimal damping and slow sound in ducts

    Author : Zhe Zhang; Mats Åbom; Hans Bodén; Lars Enghardt; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : The thesis is dedicated to expanding knowledge on two duct acoustic issues including: 1) the optimal damping of low frequency sound and 2) the development and application of ‘slow sound’.To address the first issue, the ‘Cremer impedance’ proposed more than half a century ago has been revisited and further developed. READ MORE

  5. 18. Effects of peripheral auditory adaptation on the discrimination of speech sounds

    Author : Francisco Lacerda; Hartmut Traunmüller; Olle Engstrand; Björn Lindblom; Louis Pols; Stockholms universitet; []
    Keywords : HUMANIORA; HUMANITIES; Adaptation; discrimination; categorical perception; Phonetics; Fonetik; Phonetics; fonetik;

    Abstract : This study investigates perceptual effects of discharge rate adaptation in the auditory-nerve fibers. Discrimination tests showed that brief synthetic stimuli with stationary formants and periodic source were better discriminated when they had an abrupt as opposed to a gradual onset (non-adapted vs adapted condition). READ MORE

  6. 19. Computational methods for the analysis and design of photonic bandgap structures

    Author : Min Qiu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photonic crystal; Photonic bandgap; Numerical analysis; Optimal design; Finite-difference time-domain method; Plane wave expansion method; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Abstract : In the present thesis, computational methods for theanalysis and design of photonic bandgap structure areconsidered. Many numerical methods have been used to study suchstructures. Among them, the plane wave expansion method is veryoften used. READ MORE

  7. 20. Numerical modelling and analysis of friction contact for turbine blades

    Author : Mohammad Afzal; Leif Kari; Viktor Berbyuk; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : High cycle fatigue failure of turbine and compressor blades due to resonance in the operating frequency range is one of the main problems in the design of gas turbine engines. To suppress excessive vibrations in the blades and prevent high cycle fatigue, dry friction dampers are used by the engine manufacturers. READ MORE