Sökning: "multigrid"

Visar resultat 1 - 5 av 24 avhandlingar innehållade ordet multigrid.

1. 1. The Full Multigrid Method Applied to Turbulent Flow in Ventilated Enclosures Using Structured and Unstructured Grids

   Författare :Peter Emvin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; adaptivity; finite volume; local mesh refinement; finite element; k-omega large Eddy simulation; ventilated enclosure; k-epsilon; multigrid;

   Sammanfattning : Computational fluid dynamics require large computer resources and it is thus of paramount interest to have as efficient an algorithm as possible. This means that both an accurate discretization and a fast solver are required. In this work, we have used the full multigrid concept, which is a general and optimal solver. LÄS MER

3. 2. Accuracy and Convergence Studies of the Numerical Solution of Compressible Flow Problems

   Författare :Erik Sterner; Per Lötstedt; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; computational fluid dynamics; Navier-Stokes equations; convergence acceleration; preconditioning; semi-implicit; multiblock; multigrid; finite volume method; Numerical Analysis; Numerisk analys;

   Sammanfattning : The numerical solution of compressible flow problems governed by the Navier-Stokes equations is considered. A finite volume method is used for the discretization in space. Different techniques to accelerate the convergence to a steady state are suggested, and the accuracy of the spatial difference operator is analyzed. LÄS MER

4. 3. Computational Solid Wave Propagation Numerical Techniques and Industrial Applications

   Författare :Torbjörn Ekevid; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wave propagation; multigrid; adaptivity; parallel; FEM; iterative; SBFEM;

   Sammanfattning : For wave propagation and many other physical phenomena, the dynamic effects are vital. In industrial applications, such problems are very complex and generally have to be treated by means of numerical methods. LÄS MER

5. 4. Computational Characterization of Mixing in Flows

   Författare :Erik D. Svensson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mixing; hyperbolicity; shadowing; finite elements; flow simulation; a priori error estimates; Stokes equations; point location; multigrid; refinements; mixing;

   Sammanfattning : The major theme of this thesis is mathematical aspects of fluid mixing in the case when diffusion is negligible, which is commonly refered to as ’mixing by stirring’ or ’mixing by chaotic advection’ in the engineering literature. In this case the mixing is driven by a velocity field and is characterized by the flow generated by the velocity field. LÄS MER

7. 5. Iterative and Adaptive PDE Solvers for Shared Memory Architectures

   Författare :Henrik Löf; Jarmo Rantakokko; Sverker Holmgren; Erik Hagersten; Mark Bull; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; partial differential equations; iterative methods; finite elements; conjugate gradients; adaptive mesh refinement; multigrid; cc-NUMA; distributed shared memory; OpenMP; page migration; TLB shoot-down; bandwidth minimization; reverse Cuthill-McKee; migrate-on-next-touch; affinity; temporal locality; chip multiprocessors; CMP; Beräkningsvetenskap; Scientific Computing;

   Sammanfattning : Scientific computing is used frequently in an increasing number of disciplines to accelerate scientific discovery. Many such computing problems involve the numerical solution of partial differential equations (PDE). LÄS MER