Sökning: "Boundary layers"

Visar resultat 1 - 5 av 211 avhandlingar innehållade orden Boundary layers.

  1. 1. Studies of stratocumulus-topped boundary layers using a numerical weather prediction model

    Författare :Robert Sigg; Peter Duynkereke; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; meteorologi; Meteorology;

    Sammanfattning : Persistent stratocumulus clouds are commonly observed in many areas on Earth. In general, stratocumulus clouds cool the Earth-atmosphere system due to their influence on the radiation budget. It is therefore essential to describe such clouds accurately in climate and numerical weather prediction models. LÄS MER

  3. 2. Simulations of turbulent boundary layers with suction and pressure gradients

    Författare :Alexandra Bobke; Philipp Schlatter; Ramis Örlü; Ayse Gul Gungor; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layers; near-wall turbulence; history effects; asymptotic suction boundary layers; large-eddy simulation;

    Sammanfattning : The focus of the present licentiate thesis is on the effect of suction and pressure gradients on turbulent boundary-layer flows, which are investigated separately through performing numerical simulations.The first part aims at assessing history and development effects on adverse pressure-gradient (APG) turbulent boundary layers (TBL). LÄS MER

  4. 3. Receptivity of crossflow-dominated boundary layers

    Författare :David Tempelmann; Ardeshir Hanifi; Dan Henningson; Anatoli Tumin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Receptivity; three-dimensional boundary layers; optimal growth; adjoint solutions; swept wing;

    Sammanfattning : This thesis deals with receptivity mechanisms of three-dimensional, crossflow-dominated boundary layers. The receptivity of two model problems, a swept-flat-plate and a swept-wing boundary layer, is investigated by solving the parabolised stability equations (PSE) as well as by performing direct numerical simulations (DNS). LÄS MER

  5. 4. Wings, turbulent boundary layers and flow separation

    Författare :Fermin Mallor; Philipp Schlatter; Ricardo Vinuesa; Ramis Örlü; Manuel García Villalba; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wings; turbulent boundary layers; adverse pressure gradients; flow separation; numerical simulations; wind-tunnel experiments; flow control.; Vingar; turbulenta gränsskikt; negativa tryckgradienter; avlösning; numeriska simuleringar; vindtunnel-experiment; flow control; Aerospace Engineering; Flyg- och rymdteknik; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : The present doctoral thesis investigates the turbulent flow developing around wing sections, focusing on the impact of adverse-pressure-gradient (APG) conditions on turbulent boundary layers (TBLs) and the physics of flow separation. Both experimental and numerical methods are employed to generate high-fidelity data sets and provide an in-depth analysis of the flow. LÄS MER

  7. 5. Boundary layers over wing sections

    Författare :Prabal Negi; Dan Henningson; Spencer Sherwin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : The understanding of developing boundary layers over wings is an important topic from the perspective of industrial applications. An increased understanding would be consequential not only for achieving higher fuel efficiency but also in the design of aircraft control strategies. LÄS MER