Sökning: "Incompressible flow"

Visar resultat 1 - 5 av 69 avhandlingar innehållade orden Incompressible flow.

  1. 1. Stability of plane Couette flow and pipe Poiseuille flow

    Författare :Per-Olov Åsén; Gunilla Kreiss; Jonathan Goodman; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrodynamic stability; plane Couette flow; pipe Poiseuille flow; direct numerical simulations; resolvent; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : This thesis concerns the stability of plane Couette flow and pipe Poiseuille flow in three space dimensions. The mathematical model for both flows is the incompressible Navier--Stokes equations. Both analytical and numerical techniques are used. We present new results for the resolvent corresponding to both flows. LÄS MER

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

    Författare :Lars Carlsson; Chalmers University of Technology; []
    Nyckelord :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. 3. Numerical Study of Laminar, Transitional and Turbulent Flow Past Rectangular Cylinders

    Författare :Ahmad Sohankar Esfahani; Chalmers University of Technology; []
    Nyckelord :blockage; outlet boundary condition; rectangular cylinders; onset of vortex shedding; angle of incidence; incompressible flow; LES; DNS; transition; finite volumes; Reynolds number; numerical simulation; square cylinder;

    Sammanfattning : The subject of flow past slender bluff bodies is of relevance to technical problems associated with energy conservation, structural design and acoustic emissions. The present work is restricted to an important sub-class of slender bluff body flow --- the incompressible flow around a stationary cylinder having a rectangular cross section, the cylinder being exposed to a constant free stream velocity. LÄS MER

  4. 4. Weld Pool Simulations

    Författare :Marcus Edstorp; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; Arc Welding; Weld Pool; Multiphysics Simulations; Moving Boundaries; Free Surfaces; Mesh Motion; Two-Phase Flow; Incompressible Flow; Electromagnetics; Finite Element Methods; Arc Welding; Applied mathematics; Tillämpad matematik; Manufacturing engineering; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : This investigation is devoted to the study of welding and its effect on the workpiece, focusing on the thermo and fluid dynamical phenomena occuring during a autogenous or nonautogenous arc fusion welding process. Its aim is to simulate the behaviour of the weld pool and analyze the consequence of the solid-liquid phase change, thus obtaining a methodology for predicting the appearance of weld defects related to solidification and cooling. LÄS MER

  5. 5. Towards Full Predictions of the Unsteady Incompressible Flow in Rotating Machines, Using OpenFOAM

    Författare :Olivier Petit; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulent Flow; Sliding Grid; Hydro Power; Kaplan Turbine; OpenFOAM; CFD;

    Sammanfattning : The main objective of the present work is to validatemethodologies for accurate numerical predictions of the incompressible flow ofwater in the U9 Kaplan turbine model. The term “prediction” implies that the useof detailed experimental data for boundary conditions should be avoided, andthat all important features of the studied case should be included. LÄS MER