Sökning: "Navier-Stokes"

Visar resultat 6 - 10 av 211 avhandlingar innehållade ordet Navier-Stokes.

1. 6. Towards Accurate Numerical Methods for Ship Flows on Composite Overlapping Grids

   Författare :Lars Carlsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer; wake; incompressible flow; Navier-Stokes; composite overlapping grids; grid generation; ship flow; parallel computing; alternating-direction implicit; line-implicit;

   Sammanfattning : Numerical methods are presented that are designed to make accurate ship-flow computations more feasible. One method concerns the automatic generation of high-quality computational grids. It treats the grids as competing individuals in a population, where an individual's fitness is based on a measure of grid quality. LÄS MER

3. 7. Numerical Simulation of Turbulent Flows for Turbine Blade Heat Transfer Applications

   Författare :Jonas Larsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; k-.omega.; k-.epsilon.; explicit Runge-Kutta; finite volume; turbine; numerical method; non-linear; Navier-Stokes; supersonic; two-equation; external heat transfer; stagnation flow; two-dimensional; transition; low-Reynolds; turbulence model; impulse blade;

   Sammanfattning : Turbine blade heat transfer is an important engineering problem characterized by complex flow fields and high turbulence levels. This thesis is focused on using a full Navier-Stokes solver with two-equation eddy-viscosity models to predict external heat-transfer in single-stage, linear, two-dimensional uncooled turbine cascades. LÄS MER

4. 8. An Object-Oriented Framework for PDE Solvers

   Författare :Krister Åhlander; Michael Thuné; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PDE; Navier-Stokes; object-oriented; overlapping grids; Numerical Analysis; Numerisk analys;

   Sammanfattning : The issue of how to develop reusable software in scientific computing is addressed. With object-oriented analysis and design, an extendable set of collaborating objects - a framework named COMPOSE - is suggested in the area of "PDE solvers", i.e., programs that numerically solve partial differential equations (PDEs). LÄS MER

5. 9. Data Partitioning Methods and Parallel Block-Oriented PDE Solvers

   Författare :Jarmo Rantakokko; Michael Thuné; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; data assimilation; data partitioning; meteorology; multiblock; Navier-Stokes; object-oriented; oceanography; parallel computing; Numerical Analysis; Numerisk analys;

   Sammanfattning : Data partitioning methods for block-structured problems within scientific computing have been studied. The applications are variational data assimilation in meteorology, ocean modeling, and airflow simulation with multiblock grids. LÄS MER

7. 10. Potential Flow Panel Methods for the Calculation of Free-surface Flows with Lift

   Författare :Carl-Erik Janson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; desingularized; shape optimization; Rankine source; waves; OCTOPUS; dipole; MMA; Dawson operator; boundary layer; vortex; Method of Moving Asymptotes; nonlinear; sailing yacht; four point operator; surface piercing wing; Navier-Stokes; numerical method; lift force; raised panel method; discrete Fourier transform; collocation point shift; potential flow; CFD; free surface; induced drag; SHIPFLOW; dispersion; damping; analytical method; hydrofoil;

   Sammanfattning : Two non-linear Rankine-source panel methods are developed and implemented in the same computer code. The first method uses a four-point upwind operator on the free-surface to compute the velocity derivatives and to enforce the radiation condition while the second method uses an analytical expression for the velocity derivatives and a collocation point shift one panel upstream to prevent upstream waves. LÄS MER