Sökning: "boundary layer approximation"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden boundary layer approximation.

  1. 1. Mesoscale dynamics and boundary-layer structure in topographically forced low-level jets

    Författare :Stefan Söderberg; Michael Tjernström; Branko Grisogono; Douw G. Steyn; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; low-level jets; boundary layer; turbulence structure; Meteorology; Meteorologi;

    Sammanfattning : Two types of mesoscale wind-speed jet and their effects on boundary-layer structure were studied. The first is a coastal jet off the northern California coast, and the second is a katabatic jet over Vatnajökull, Iceland. LÄS MER

  3. 2. Numerical studies of bypass transition in the Blasius boundary layer

    Författare :Luca Brandt; KTH; []
    Nyckelord :Fluid Mechanics; laminar-turbulent transition; boundary layer flow; transient growth; streamwise streaks; secondary instability;

    Sammanfattning : Experimental findings show that transition from laminar toturbulent ow may occur also if the exponentially growingperturbations, eigensolutions to the linearised disturbanceequations, are damped. An alternative non-modal growthmechanism has been recently identi fied, also based on thelinear approximation. LÄS MER

  4. 3. Study of generation, growth and breakdown of streamwise streaks in a Blasius boundary layer

    Författare :Luca Brandt; KTH; []
    Nyckelord :Fluid mechanics; laminar-turbulent transition; boundary layer flow; transient growth; streamwise streaks; lift-up effect; receptivity; free-stream turbulence; streak instability; secondary instability; Direct Numerical Simulation.;

    Sammanfattning : Transition from laminar to turbulent flow has beentraditionally studied in terms of exponentially growingeigensolutions to the linearized disturbance equations.However, experimental findings show that transition may occuralso for parameters combinations such that these eigensolutionsare damped. LÄS MER

  5. 4. Boundary Layer Approximate Approximations and Cubature of Potentials in Domains

    Författare :Tjavdar Ivanov; Per Lötstedt; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The goal of this thesis is to develop efficient numerical algorithms for approximation of functions defined on domains and apply these algorithms to obtain accurate semi-analytic cubature formulae for various integral operators. These algorithms are based on the method of "approximate approximations", introduced by V. Maz'ya in 1991. LÄS MER

  7. 5. Wall Related Lean Premixed Combustion Modeled with Complex Chemistry

    Författare :Johan Andrae; KTH; []
    Nyckelord :Wall effects; premixed flames; flame quenching; numerical modeling; chemkin; boundary layer approximation; gasified biomass; fuel-NOx; hybrid catalytic combustor.; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : Increased knowledge into the physics and chemistrycontrolling emissions from flame-surface interactions shouldhelp in the design of combustion engines featuring improvedfuel economy and reduced emissions. The overall aim of this work has been to obtain afundamental understanding of wall-related, premixed combustionusing numerical modeling with detailed chemical kinetics. LÄS MER