Sökning: "hybrid grids"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden hybrid grids.

  1. 1. 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

  3. 2. Hybrid energy storage systems : Capacity optimization and environmental implication of hybrid energy storage systems in renewable power systems

    Författare :Yang Jiao; Daniel Månsson; Alfred Rufer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Electricity production contributes a large share of greenhouse gas emissions that lead to climate change. At present, power generation in many parts of the world still heavily depends on fossil fuels. To prevent global warming, the electricity sector is supposed to transition from the current fuel mix to renewable energy sources. LÄS MER

  4. 3. Micro-grids supplied by renewable energy : Improving technical and social feasibility

    Författare :Caroline Bastholm; Ewa Wäckelgård; Annette Henning; Frank Fiedler; Kirsten Ulsrud; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rural electrification; Electricity access; Decentralized; Off-grid; Photovoltacs; PV-hybrid; Micro-grid; Multi-disciplinary; Sociotechnical; Engineering Science; Teknisk fysik; Energy and Built Environments;

    Sammanfattning : Universal access to electricity stands high on the global agenda and is regarded as essential for positive development in sectors such as health care, education, poverty reduction, food production and climate change. Decentralized, off-grid electrification is deemed an important complement to centralized grid extension. LÄS MER

  5. 4. 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

  7. 5. Hybrid Methods for Unsteady Fluid Flow Problems in Complex Geometries

    Författare :Jing Gong; Jan Nordström; Gunilla Efraimsson; Mark H. Carpenter; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hybrid methods; finite difference methods; finite volume methods; coupling procedure; stability; efficiency; artificial dissipation; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Beräkningsvetenskap med inriktning mot numerisk analys;

    Sammanfattning : In this thesis, stable and efficient hybrid methods which combine high order finite difference methods and unstructured finite volume methods for time-dependent initial boundary value problems have been developed. The hybrid methods make it possible to combine the efficiency of the finite difference method and the flexibility of the finite volume method. LÄS MER