Search for dissertations about: "fractional step"

Showing result 1 - 5 of 12 swedish dissertations containing the words fractional step.

  2. 1. Simulation of Chemical Reactors

    Author : Tommy Hertzberg; Avdelningen för kemiteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid flow; chemical reactors; formox; fractional step; catalytic combustion; Spectral methods; self-adjoint operator; Chemical technology and engineering; Kemiteknik och kemisk teknologi;

    Abstract : This thesis consists basically of two parts. They are, however, interrelated by the fact that both parts concerns modelling of catalytic reaction systems and also by the fact that in both parts, spectral methods are used for simulation. The first part describes the numerical treatment of the dispersion model. READ MORE

  4. 2. Adaptive finite element methods for multiphysics problems

    Author : Fredrik Bengzon; Mats Larson; Harald van Brummelen; Umeå universitet; []
    Keywords : finite element methods; multiphysics; a posteriori error estimation; duality; adaptivity; discontinuous Galerkin; fractional step methods;

    Abstract : In this thesis we develop and analyze the performance ofadaptive finite element methods for multiphysics problems. Inparticular, we propose a methodology for deriving computable errorestimates when solving unidirectionally coupled multiphysics problemsusing segregated finite element solvers. READ MORE

  5. 3. Wideband THz Mixers and Components for the Next Generation of Receivers for Radioastronomy

    Author : Cristian Daniel López; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spectroscopy; Heterodyne receivers; Finline; Superconductor-Insulator-Superconductor SIS mixers.; Waveguide-to-Substrate Transition; Waveguide twist;

    Abstract : In recent decades, there has been a growing interest in THz research, leading to substantial improvements in technology and the emergence of new applications. In particular, the ever-evolving field of radio astronomy instrumentation has been pushing the limits of millimeter and sub-millimeter technology boundaries, redefining the state-of-the-art for wideband low-noise receivers. READ MORE

  6. 4. Nonlinear optimization approaches to H2-norm based LPV modelling and control

    Author : Daniel Petersson; Lennart Ljung; Johan Löfberg; Henrik Sandberg; Linköpings universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automatic control; Reglerteknik;

    Abstract : To be able to analyze certain classes of non-linear systems, it is necessary to try to represent them as linear parameter varying systems or even as linear fractional representations. For linear parameter varying systems and linear fractional representations of systems there exists many advanced analysis methods such as IQC-analysis and μ-analysis. READ MORE

  7. 5. Inside Pulsating White Dwarfs: Clues from time-resolved spectroscopy

    Author : Rubina Kotak; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; pulsating white dwarfs; convection; asteroseismology; Astronomi; Astronomy; spectroscopy; Fysicumarkivet A:2002:Kotak;

    Abstract : Several analyses using time-resolved optical spectrocopy of pulsating white dwarfs are presented. The data have been put to a number of uses. First, line-of-sight velocities associated with the pulsations have been measured in three hydrogen-atmosphere white dwarfs (DAVs), bringing the total number of such measurements up to five. READ MORE