Sökning: "hybrid solver"

Visar resultat 1 - 5 av 38 avhandlingar innehållade orden hybrid solver.

  1. 1. Hybrid Solvers for the Maxwell Equations in Time-Domain

    Författare :Fredrik Edelvik; Per Lötstedt; Jan Hesthaven; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; time-domain; finite volume methods; finite element methods; hybrid solver; dispersive materials; thin wires; Beräkningsvetenskap; Scientific Computing;

    Sammanfattning : The most commonly used method for the time-domain Maxwell equations is the Finite-Difference Time-Domain method (FDTD). This is an explicit, second-order accurate method, which is used on a staggered Cartesian grid. The main drawback with the FDTD method is its inability to accurately model curved objects and small geometrical features. LÄS MER

  3. 2. Hybrid Grid Generation for Viscous Flow Computations Around Complex Geometries

    Författare :Lars Tysell; Laszlo Fuchs; Nigel P. Weatherill; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; grid generation; unstructured grids; hybrid grids; surface grids; three-dimensional grids; adaptive grids; moving grids; grid quality; accuracy; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : A set of algorithms building a program package for the generation of twoandthree-dimensional unstructured/hybrid grids around complex geometrieshas been developed. The unstructured part of the grid generator is based on the advancing frontalgorithm. LÄS MER

  4. 3. Direct and Inverse Methods for Waveguides and Scattering Problems in the Time Domain

    Författare :Erik Abenius; Per Lötstedt; Mats Gustafsson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; time-domain; FDTD; finite-element; hybrid; thin sheet; waveguide; PML; inverse scattering; adjoint; gradient-based; minimization; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Numerical simulation is an important tool in understanding the electromagnetic field and how it interacts with the environment. Different topics for time-domain finite-difference (FDTD) and finite-element (FETD) methods for Maxwell's equations are treated in this thesis. LÄS MER

  5. 4. Numerical simulation and analysis of multi-scale cavitating flows using a hybrid mixture-bubble model

    Författare :Ebrahim Ghahramani; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Homogeneous mixture model; Lagrangian bubble model; CFD; Cavitation; OpenFOAM; Multiphase flow; Hybrid model; Multi-scale;

    Sammanfattning : The aim of this research is to model and analyse multi-scale cavitating flows with a certain emphasis on small sub-grid vapour structures. Cavitating flows include vapour structures with different length scales, from micro-bubbles to large cavities. LÄS MER

  7. 5. A parallel, iterative method of moments and physical optics hybrid solver for arbitrary surfaces

    Författare :Johan Edlund; Per Lötstedt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

    Sammanfattning : We have developed an MM–PO hybrid solver designed to deliver reasonable accuracy inexpensively in terms of both CPU-time and memory demands. The solver is based on an iterative block Gauss–Seidel process to avoid unnecessary storage and matrix computations, and can be used to solve the radiation and scattering problems for both disjunct and connected regions. LÄS MER