Sökning: "Direkt numerisk simulering"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Direkt numerisk simulering.

1. 1. Analysis and numerical methods for multiscale problems in magnetization dynamics

   Författare :Lena Leitenmaier; Olof Runborg; Carlos Garcia-Cervera; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

   Sammanfattning : This thesis investigates a multiscale version of the Landau-Lifshitz equation and how to solve it using the framework of Heterogeneous Multiscale Methods (HMM). The Landau-Lifshitz equation is the governing equation in micromagnetics, modeling magnetization dynamics. LÄS MER

3. 2. Topology optimization of transitional flows

   Författare :Harrison Nobis; Dan Henningson; Philipp Schlatter; Paolo Luchini; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct Numerical Simulation; Topology Optimization; Laminar– Turbulent Transition; Spectral Element Method; Direkt numerisk simulering; topologioptimering; laminär–turbulent omslag; spektralelementmetod; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : This thesis is concerned with the application of topology optimization in thedesign of structures that control fluids. A framework is developed in the high-order Spectral Element Method (SEM) code Nek5000, extending Nek5000 fromits original capabilities, performing Direct Numerical Simulations (DNS), toperforming density-based topology optimization. LÄS MER

4. 3. CFD Study of Molten Pool Convection in a Reactor Vessel during a Severe Accident

   Författare :Boshen Bian; Walter Villanueva; Sevostian Bechta; Weimin Ma; Shuisheng He; KTH; []
   Nyckelord :Severe accident; Corium; Natural convection; Turbulence; Scalability; Direct numerical simulation DNS .; Svåra haverier; härdsmälta; naturlig konvektion; turbulens; skalbarhet; direkt numerisk simulering DNS .; Physics; Fysik;

   Sammanfattning : During severe accidents in nuclear reactors, the core and internal structures can melt down and relocate into the reactor pressure vessel (RPV) lower head (LH) forming there a stratified molten corium pool. The pool generally consists of superheated oxidic and metallic liquid layers imposing thermo-mechanical loads on the RPV wall. LÄS MER

5. 4. Multiscale Methods for Wave Propagation Problems

   Författare :Henrik Holst; Björn Engquist; Olof Runborg; Assyr Abdulle; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Simulations of wave propagation in heterogeneous media and at high frequencies are important in many applications such as seismic-, {electro-magnetic-,} acoustic-, fluid flow problems and others. These are classical multiscale problems and often too computationally expensive for direct numerical simulation. LÄS MER

7. 5. High Performance Adaptive Finite Element Methods : With Applications in Aerodynamics

   Författare :Niclas Jansson; Johan Hoffman; Johan Jansson; Vincent Heuveline; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The massive computational cost for resolving all scales in a turbulent flow makes a direct numerical simulation of the underlying Navier-Stokes equations impossible in most engineering applications. Recent advances in adaptive finite element methods offer a new powerful tool in Computational Fluid Dynamics (CFD). LÄS MER