Sökning: "high order accuracy"

Visar resultat 16 - 20 av 516 avhandlingar innehållade orden high order accuracy.

1. 16. Summation-by-Parts Finite Difference Methods for Wave Propagation and Earthquake Modeling

   Författare :Vidar Stiernström; Ken Mattsson; Mark H. Carpenter; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Finite difference method; high-order accuracy; stability; summation-by-parts; wave propagation; earthquake modeling; inverse problems; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : Waves manifest in many areas of physics, ranging from large-scale seismic waves in geophysics down to particle descriptions in quantum physics. Wave propagation may often be described mathematically by partial differential equations (PDE). Unfortunately, analytical solutions to PDEs are in many cases notoriously difficult to obtain. LÄS MER

3. 17. Stable Numerical Methods with Boundary and Interface Treatment for Applications in Aerodynamics

   Författare :Sofia Eriksson; Jan Nordström; Gunilla Kreiss; Thomas Hagstrom; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; summation by parts; simultaneous approximation term; accuracy; stability; finite difference methods; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : In numerical simulations, problems stemming from aerodynamics pose many challenges for the method used. Some of these are addressed in this thesis, such as the fluid interacting with objects, the presence of shocks, and various types of boundary conditions. LÄS MER

4. 18. 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

5. 19. Controlling the dynamic characteristics of machining systems through consciously designed joint interfaces

   Författare :Constantinos Frangoudis; Cornel Mihai Nicolescu; Amir Rashid; Bulent Tasdelent; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Production; machine tool; machining system control; joint interfaces; JIM; stiffness; damping; vibrations; machining process; milling; turning; deflections; accuracy; dynamic response;

   Sammanfattning : The precision of machining systems is ever increasing in order to keep up with components’ accuracy requirements. At the same time product variants areincreasing and order quantities are decreasing, which introduces high demands on the capability of machining systems. LÄS MER

7. 20. Numerics of Elastic and Acoustic Wave Motion

   Författare :Kristoffer Virta; Gunilla Kreiss; Anders Petersson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite differences; stability; high order accuracy; elastic wave equation; acoustic wave equation; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : The elastic wave equation describes the propagation of elastic disturbances produced by seismic events in the Earth or vibrations in plates and beams. The acoustic wave equation governs the propagation of sound. LÄS MER