Sökning: "adaptive grids"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden adaptive 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. Quality Assurance of Time Critical Data Using Adaptive Data Delivery Mechanisms in Smart Grids

    Författare :Yiming Wu; Lars Nordström; Chen-Ching Liu; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; time critical data quality; adaptive mechanisms; quality assurance; Smart Grid; information resiliency; data accuracy; end-to-end latency; cyber-security; substation automation; power system communication; Electrical Engineering; Elektro- och systemteknik; Industrial Information and Control Systems; Industriella informations- och styrsystem;

    Sammanfattning : Smart grids are proposed to integrate renewable energy and to improve the efficiency of power system operation. The challenges of integrating renewable energy are the inherent fluctuations of generation which are difficult to predict which may lead to challenges to the safe operation of power systems. LÄS MER

  4. 3. Efficient Partitioning of Dynamic Structured Grid Hierarchies

    Författare :Johan Steensland; Michael Thuné; Jarmo Rantakokko; Charles Norton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; scientific computing; partitioning; structured grids; adaptive mesh refinement; dynamic load balancing; Beräkningsvetenskap; Scientific Computing;

    Sammanfattning : This thesis aims at decreasing execution time for large-scale structured adaptive mesh refinement (SAMR) applications executing on general parallel computers. The key contributions are (1) A conceptual dynamically adaptive meta-partitioner able to select and configure an appropriate partitioning technique, based on application and computer state, and (2) A characterization of new and existing domain-based partitioners, enabling a mapping from application and computer state onto appropriate partitioners, and (3) Sketched scalable solutions, expressed in terms of natural regions and expert algorithms, for the problem to efficiently partition large-scale SAMR applications with deep grid hierarchies executing on general parallel computers, and (4) A software partitioning tool Nature+Fable, implementing the greater parts of these sketched scalable solutions and engineered as part of the meta-partitioner. LÄS MER

  5. 4. Adaptive Solvers for High-Dimensional PDE Problems on Clusters of Multicore Processors

    Författare :Magnus Grandin; Sverker Holmgren; Michael Thuné; Michael Bader; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; adaptive mesh refinement; anisotropic refinement; exponential integrators; Lanczos algorithm; hybrid parallelization; time-dependent Schrödinger equation; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : Accurate numerical solution of time-dependent, high-dimensional partial differential equations (PDEs) usually requires efficient numerical techniques and massive-scale parallel computing. In this thesis, we implement and evaluate discretization schemes suited for PDEs of higher dimensionality, focusing on high order of accuracy and low computational cost. LÄS MER

  7. 5. Adaptive time-integration for goal-oriented and coupled problems

    Författare :Peter Meisrimel; Numerisk analys; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; time-adaptivity; goal-oriented problems; error estimation; coupled problems; waveform relaxation; asynchronous methods; conjugate heat transfer;

    Sammanfattning : We consider efficient methods for the partitioned time-integration of multiphysics problems, which commonly exhibit a multiscale behavior, requiring independent time-grids. Examples are fluid structure interaction in e.g., the simulation of blood-flow or cooling of rocket engines, or ocean-atmosphere-vegetation interaction. LÄS MER