Sökning: "vortex generators"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden vortex generators.

  1. 1. Vortex generators and turbulent boundary layer separation control

    Författare :Ola Lögdberg; Henrik Alfredsson; Per-Åge Krogstad; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulent boundary layer separation; adverse pressure gradient; vortex generators; control of separation; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : Boundary layer separation is usually an unwanted phenomenon in most technical applications as for instance on airplane wings, on ground vehicles and in internal flows such as diffusers. If separation occurs it leads to loss of lift, higher drag and results in energy losses. LÄS MER

  3. 2. Turbulent Boundary Layer Separation and Control

    Författare :Ola Lögdberg; P. Henrik Alfredsson; Jens Fransson; Guido Buresti; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow control; adverse pressure gradient APG ; flow separation; vortex generators; jet vortex generators; pulsed jet vortex generators; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : Boundary layer separation is an unwanted phenomenon in most technical applications, as for instance on airplane wings, ground vehicles and in internal flow systems. If separation occurs, it causes loss of lift, higher drag and energy losses. It is thus essential to develop methods to eliminate or delay separation. LÄS MER

  4. 3. Computational studies of passive vortex generators for flow control

    Författare :Florian von Stillfried; Arne Johansson; Stefan Wallin; Sinisa Krajnovic; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; passive flow control; vortex generator; statistical modelling; turbulence; separation prevention; flat plate; diffuser; high-lift design; airfoil; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : Many flow cases in fluid dynamics face undesirable flow separation due torising static pressure on wall boundaries. This occurs e.g. due to geometry as ina highly curved turbine inlet duct or e. LÄS MER

  5. 4. Vortex generator modeling and its application to optimal control of airflow in inlet

    Författare :Adam Jirásek; Arthur Rizzi; John W Slater; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vortex generator; vortex generator model; flow control; design and optimization; DOE; CFD; UAV; inlet; S-duct; pressure distortion; pressure recovery; Vehicle engineering; Farkostteknik;

    Sammanfattning : This dissertation deals with the development of the vortex generator model and its use for the optimization study of vortex generator flow control in high-offset-ed inlets. In the first part, the overview of use of vortex generators and their mechanism is outlined. LÄS MER

  7. 5. Computational fluid-dynamics investigations of vortex generators for flow-separation control

    Författare :Florian von Stillfried; Arne Johansson; Stefan Wallin; Jonathan Morrison; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow-separation control; vane vortex generator; vortex generator jet; zero-pressure-gradient turbulent boundary layer; adverse-pressure-gradient turbulent boundary layer; statistical modelling; turbulence; Reynolds stress- transport model; computational fluid dynamics;

    Sammanfattning : Many flow cases in fluid dynamics face undesirable flow separation due to ad-verse pressure gradients on wall boundaries. This occurs, for example, due togeometrical reasons as in a highly curved turbine-inlet duct or on flow-controlsurfaces such as wing trailing-edge flaps within a certain angle-of-attack range. LÄS MER