Sökning: "Incompressible flow"

Visar resultat 6 - 10 av 75 avhandlingar innehållade orden Incompressible flow.

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

    Författare :Olivier Petit; Chalmers tekniska högskola; []
    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

  3. 7. Global stability and feedback control of boundary layer flows

    Författare :Espen Åkervik; Dan S. Henningson; Luca Brandt; Dwight Barkley; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stability; Global Stability; Feedback Control; Control; Estimation; Absolute Convective Instabilities; Model Reduction; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : In this thesis the stability of generic boundary layer flows is studied from a global viewpoint using optimization methods. Global eigenmodes of the incompressible linearized Navier-Stokes equations are computed using the Krylov subspace Arnoldi method. LÄS MER

  4. 8. 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

  5. 9. Mass Conserving Simulations of Two Phase Flow

    Författare :Elin Olsson; Gunilla Kreiss; Stig Larsson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; free boundary; two phase flow; level set method; conservative; Numerical analysis; Numerisk analys;

    Sammanfattning : Consider a mixture of two immiscible, incompressible fluids e.g. oil and water. Since the fluids do not mix, an interface between the two fluids will form and move in time. LÄS MER

  7. 10. Computational Techniques for Coupled Flow-Transport Problems

    Författare :Martin Kronbichler; Gunilla Kreiss; Jean-Luc Guermond; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Finite element method; saddle point systems; two-phase flow; level set method; phase field method; stabilization; contact line dynamics; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : This thesis presents numerical techniques for solving problems of incompressible flow coupled to scalar transport equations using finite element discretizations in space. The two applications considered in this thesis are multi-phase flow, modeled by level set or phase field methods, and planetary mantle convection based on the Boussinesq approximation. LÄS MER