Sökning: "gauss"

Visar resultat 26 - 30 av 46 avhandlingar innehållade ordet gauss.

  1. 26. Acceleration of Compressible Flow Simulations with Edge Using  Implicit Time Stepping

    Författare :Evelyn Otero; Arthur Rizzi; Richard P. Dwight; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Compressible CFD; Convergence Acceleration; Implicit Time-Stepping; LU-SGS; Upwind Type Dissipation; Line-implicit; Ordering; Parallelization; Parameters; Multigrid;

    Sammanfattning : Computational fluid dynamics (CFD) is a significant tool routinely used indesign and optimization in aerospace industry. Often cases with unsteadyflows must be computed, and the long compute times of standard methods hasmotivated the present work on new implicit methods to replace the standardexplicit schemes. LÄS MER

  3. 27. Acceleration of Compressible Flow Simulations with Edge using Implicit Time Stepping

    Författare :Evelyn Otero; Arthur Rizzi; Jesper Oppelstrup; Per Wahlund; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; compressible CFD; convergence acceleration; implicit time-stepping; matrix dissipation; line-implicit; performance optimization;

    Sammanfattning : Computational fluid dynamics (CFD) has become a significant tool routinely used in design and optimization in aerospace industry. Typical flows may be characterized by high-speed and compressible flow features and, in many cases, by massive flow separation and unsteadiness. LÄS MER

  4. 28. Efficient and Reliable Simulation of Quantum Molecular Dynamics

    Författare :Katharina Kormann; Sverker Holmgren; Gunilla Kreiss; Hans O. Karlsson; Christian Lubich; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; time-dependent Schrödinger equation; quantum optimal control; exponential integrators; spectral elements; radial basis functions; global error control and adaptivity; high-performance computing implementation; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : The time-dependent Schrödinger equation (TDSE) models the quantum nature of molecular processes.  Numerical simulations based on the TDSE help in understanding and predicting the outcome of chemical reactions. LÄS MER

  5. 29. Novel beam shaping and computer vision methods for laser beam welding

    Författare :Yongcui Mi; Antonio Ancona; Fredrik Sikström; Isabelle Choquet; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser beam welding; Beam shaping; Deformable mirror; Process monitoring; Process control; Model validation; Computer vision; Machine learning; Butt joint; T-joint.; Lasersvetsning; Beam shaping; Deformerbar spegel; Processövervakning; Processkontroll; Modellvalidering; Datorsyn; Maskininlärning; Butt joint; T-fogar;

    Sammanfattning : Laser beam welding has been widely applied in different industrial sectors due to its unique advantages. However, there are still challenges, such as beam positioning in T-joint welding, and gap bridging in butt joint welding,especially in the case of varying gap width along a joint. LÄS MER

  7. 30. Multigrid Preconditioners for the Discontinuous Galerkin Spectral Element Method : Construction and Analysis

    Författare :Lea Miko Versbach; Numerisk analys; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Discontinuous Galerkin Method; Finite Volume Method; Implicit Schemes; Local Fourier Analysis; Multigrid Method; Preconditioner; Space-Time Discretization; Spectral Element Method;

    Sammanfattning : Discontinuous Galerkin (DG) methods offer a great potential for simulations of turbulent and wall bounded flows with complex geometries since these high-order schemes offer a great potential in handling eddies. Recently, space-time DG methods have become more popular. LÄS MER