Search for dissertations about: "computational stability"

Showing result 1 - 5 of 291 swedish dissertations containing the words computational stability.

2. 1. Stability of the free-surface problem arising in ice-sheet- and glacier modeling : Numerical investigation and stabilization

   Author : André Löfgren; Josefin Ahlkrona; Fabien Gillet-Chaulet; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ice-sheet modeling; glacier modeling; ice-sheet dynamics; free-surface flow; stability; stabilization; free-surface stabilization algorithm; Numerical Analysis; numerisk analys;

   Abstract : This thesis consists of two papers dealing with a stabilization method for free-surface flows. The method was initially developed to stabilize mantle-convection simulations, but is in this work extended to ice-sheet- and glacier modeling. READ MORE

4. 2. Computational modeling of complex flow : Doctoral thesis at Chalmers University of Technology

   Author : Johan Hoffman; Claes Johnson; Ragnar Winter; Chalmers; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : In this thesis we consider the following aspects of computational modeling of complex flows: (i) subgrid modeling, (ii) stability, (iii) a posteriori error estimation, and (iv) computational platform. We develop a framework for adaptivity and error control for multiscale problems, in particular for turbulent flow, based on a posteriori error estimates. READ MORE

5. 3. Perfectly Matched Layers and High Order Difference Methods for Wave Equations

   Author : Kenneth Duru; Gunilla Kreiss; Jan Nordsröm; Ken Mattsson; Marcus Grote; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Elastic waves; Surface waves; Perfectly matched layers; High order difference methods; Stability; Summation-by-parts operators; Boundary treatments; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Abstract : The perfectly matched layer (PML) is a novel technique to simulate the absorption of waves in unbounded domains. The underlying equations are often a system of second order hyperbolic partial differential equations. In the numerical treatment, second order systems are often rewritten and solved as first order systems. READ MORE

6. 4. Hybrid Methods for Unsteady Fluid Flow Problems in Complex Geometries

   Author : Jing Gong; Jan Nordström; Gunilla Efraimsson; Mark H. Carpenter; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; hybrid methods; finite difference methods; finite volume methods; coupling procedure; stability; efficiency; artificial dissipation; Numerical analysis; Numerisk analys; Scientific Computing; Beräkningsvetenskap; Beräkningsvetenskap med inriktning mot numerisk analys;

   Abstract : In this thesis, stable and efficient hybrid methods which combine high order finite difference methods and unstructured finite volume methods for time-dependent initial boundary value problems have been developed. The hybrid methods make it possible to combine the efficiency of the finite difference method and the flexibility of the finite volume method. READ MORE

7. 5. Weak Boundary and Interface Procedures for Wave and Flow Problems

   Author : Qaisar Abbas; Jan Nordström; Peter Eliasson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; weak boundary conditions; multiple penalty; finite difference methods; summation-by-parts; high order scheme; hybrid methods; MUSCL scheme; shocks; stability; energy estimate; steady-state; non-reflecting; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Abstract : In this thesis, we have analyzed the accuracy and stability aspects of weak boundary and interface conditions (WBCs) for high order finite difference methods on Summations-By-Parts (SBP) form. The numerical technique has been applied to wave propagation and flow problems. READ MORE