Sökning: "incompressible flows"

Visar resultat 1 - 5 av 36 avhandlingar innehållade orden incompressible flows.

  1. 1. Symplectic methods for Hamiltonian isospectral flows and 2D incompressible Euler equations on a sphere

    Författare :Milo Viviani; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fluid dynamics; Symplectic methods; Isospectral flows; Geometric integration; Hamiltonian systems; Structure preserving algorithms; Euler equations; Lie–Possion systems; Fluid dynamics.;

    Sammanfattning : The numerical solution of non-canonical Hamiltonian systems is an active and still growing field of research. At the present time, the biggest challenges concern the realization of structure preserving algorithms for differential equations on infinite dimensional manifolds. Several classical PDEs can indeed be set in this framework. LÄS MER

  3. 2. Studies on instability and optimal forcing of incompressible flows

    Författare :Mattias Brynjell-Rahkola; Dan S. Henningson; Ardeshir Hanifi; Philipp Schlatter; François Gallaire; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrodynamic stability; optimal forcing; resolvent operator; Laplace preconditioner; spectral element method; eigenvalue problems; inverse power method; direct numerical simulations; Falkner–Skan–Cooke boundary layer; localized roughness; crossflow vortices; Blasius boundary layer; localized suction; helical vortices; lid-driven cavity; cylinder flow; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : This thesis considers the hydrodynamic instability and optimal forcing of a number of incompressible flow cases. In the first part, the instabilities of three problems that are of great interest in energy and aerospace applications are studied, namely a Blasius boundary layer subject to localized wall-suction, a Falkner–Skan–Cooke boundary layer with a localized surface roughness, and a pair of helical vortices. LÄS MER

  4. 3. Large Eddy Simulation of Complex Turbulent Flows

    Författare :Magnus Berglund; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gases; fluid dynamics; plasmas; Computational Fluid Dynamics CFD ; Large Eddy Simulation; Complex Turbulent Flows; plasma; Gaser; fluiddynamik;

    Sammanfattning : This thesis concerns the Large Eddy Simulation methodology and its application to predict complex turbulent flows at high Reynolds numbers, and at times also with high Mach numbers. The meaning of the word ?complex? refers both to the presence of complex flow phenomena and the, often, complex geometry of man-made devices restricting the flow. LÄS MER

  5. 4. Parallel computational fluid dynamics on overlapping grids

    Författare :Stefan Nilsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partition of unity; line-implicit time-integration; incompressible flows; suspension feeders; benthic boundary layers; bivalves; computational fluid dunamics; Overlapping grids; parellel computing; grid partitioning;

    Sammanfattning : .... LÄS MER

  7. 5. 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