Essays about: "Spectral Iterative Method"

Found 5 essays containing the words Spectral Iterative Method.

  1. 1. Subgrid finite volume preconditioner for Discontinuous Galerkin implemented in the DUNE framework

    University essay from Lunds universitet/Matematik LTH

    Author : Johannes Kasimir; [2021]
    Keywords : discontinuous galerkin spectral element method; dune; high performance computing; numerical analysis; numerical methods; fluid dynamics; simulation; multigrid; iterative methods; Technology and Engineering;

    Abstract : A Jacobian free multigrid preconditioner for linear problems arising from Implicit Discontinuous Galerkin (DG) discretizations is implemented. The preconditioner is based on a multigrid method for a low order Finite volume (FV) discretization on a subcellgrid. L2-projections are introduced as a strategy to translate between the discretizations. READ MORE

  2. 2. Computation of Stationary States for Rotating Bose-Einstein Condensates using Spectral Methods

    University essay from KTH/Skolan för teknikvetenskap (SCI)

    Author : Adam Erlandsson; Paul Hedvall; [2020]
    Keywords : ;

    Abstract : The Bose-Einstein condensate is a phase of matter that arises when cooling gases of bosons to extremely low temperatures. When studying these condensates one may use the Gross-Pitaevskii equation, which is a non-linear variant of the Schrödinger equation. READ MORE

  3. 3. Analytical Investigation of Planetary Gears Instabilities and the Impact of Micro-Macro Geometry Modifications

    University essay from KTH/Farkostteknik och Solidmekanik

    Author : Hamza Oudich; [2020]
    Keywords : Planetary gears; Instabilities; Resonance; Vibration; dynamic response; Spectral Iterative Method; Modal analysis; Static and dynamic transmission error; Gear mesh stiffness; Macro and micro-geometry; Phasing;

    Abstract : Due to their large torque-speed ratio and transmission efficiency, planetary gears are widely used in the automotive industry. However, high amplitude vibrations remain their critical weakness, which limits their usage especially when new strict noise legislations come into action. READ MORE

  4. 4. Blood Velocities Estimation using Ultrasound

    University essay from Lunds universitet/Matematisk statistik

    Author : Elham Pirnia; [2013]
    Keywords : Mathematics and Statistics;

    Abstract : This thesis consists of two parts. In the rst part, the iterative data-adaptive BIAA spectral estimation technique was extended to estimate lateral blood velocities using ultrasound scanners. The BIAA method makes no assumption on samples depth or sampling pattern, and therefore allows for transmission in duplex mode imaging. READ MORE

  5. 5. Nonlinear Modeling of Locomotive Propulsion System and Control

    University essay from Lunds universitet/Institutionen för reglerteknik

    Author : Henrik Sandberg; [1999]
    Keywords : Technology and Engineering;

    Abstract : In this report the motor side of a converter driven AC-locomotive is studied and modeled. The motor side consists of an asynchronous electrical engine, an indirect self controller, a voltage converter, a Pulse Width Modulator(PWM) and the train mechanics. The converter is supplied with voltage from a DC-link. READ MORE