Sökning: "high order finite difference"

Visar resultat 6 - 10 av 77 avhandlingar innehållade orden high order finite difference.

1. 6. High order summation-by-parts methods in time and space

   Författare :Tomas Lundquist; Jan Nordström; Peter Eliasson; David A. Kopriva; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; summation-by-parts; time integration; stiff problems; weak initial conditions; high order methods; simultaneous-approximation-term; finite difference; discontinuous Galerkin; spectral methods; conservation; energy stability; complex geometries; non-conforming grid interfaces; interpolation;

   Sammanfattning : This thesis develops the methodology for solving initial boundary value problems with the use of summation-by-parts discretizations. The combination of high orders of accuracy and a systematic approach to construct provably stable boundary and interface procedures makes this methodology especially suitable for scientific computations with high demands on efficiency and robustness. LÄS MER

3. 7. High-order finite difference approximations for hyperbolic problems : multiple penalties and non-reflecting boundary conditions

   Författare :Hannes Frenander; Jan Nordström; Philipp Birken; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : In this thesis, we use finite difference operators with the Summation-By-Partsproperty (SBP) and a weak boundary treatment, known as SimultaneousApproximation Terms (SAT), to construct high-order accurate numerical schemes.The SBP property and the SAT’s makes the schemes provably stable. LÄS MER

4. 8. Summation-by-Parts Operators for High Order Finite Difference Methods

   Författare :Ken Mattsson; Nordström Jan; Gunilla Kreiss; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dinite difference methods; accuracy; stability; dissipation; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Numerical Analysis;

   Sammanfattning : High order accurate finite difference methods for hyperbolic and parabolic initial boundary value problems (IBVPs) are considered. Particular focus is on time dependent wave propagating problems in complex domains. Typical applications are acoustic and electromagnetic wave propagation and fluid dynamics. LÄS MER

5. 9. High Order Finite Difference Methods with Artificial Boundary Treatment in Quantum Dynamics

   Författare :Anna Nissen; Gunilla Kreiss; Sverker Holmgren; Magnus Svärd; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Schrödinger equation; finite difference methods; perfectly matched layer; summation-by-parts operators; adaptive discretization; stability; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : The investigation of the dynamics of chemical reactions, both from the theoretical and experimental side, has drawn an increasing interest since Ahmed H. Zewail was awarded the 1999 Nobel Prize in Chemistry for his work on femtochemistry. LÄS MER

7. 10. Finite Difference Methods for Time-Dependent Wave Propagation Problems

   Författare :Ylva Ljungberg Rydin; Ken Mattsson; Erik Sjöqvist; Magnus Svärd; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Finite differences; Wave propagation problems; Summation-by-parts; Simultaneous approximation term; High-order accuracy; Deforming domains; Point sources; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Wave propagation models are essential in many fields of physics, such as acoustics, electromagnetics, and quantum mechanics. Mathematically, waves can be described by partial differential equations (PDEs).  In most cases, exact solutions to wave-dominated PDEs are nearly impossible to derive. LÄS MER