Sökning: "boundary layer"

Visar resultat 16 - 20 av 472 avhandlingar innehållade orden boundary layer.

  1. 16. On stability and receptivity of boundary-layer flows

    Författare :Nima Shahriari; Ardeshir Hanifi; Dan S. Henningson; Peter J. Schmid; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer receptivity; acoustic receptivity; swept-wing flow; crossflow vortices; roughness element; global stability analysis; direct numerical simulation; plasma actuator; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : This work is concerned with stability and receptivity analysis as well as studies on control of the laminar-turbulent transition in boundary-layer flows through direct numerical simulations. Various flow configurations are considered to address flow around straight and swept wings. LÄS MER

  3. 17. Investigations of the asymptotic suction boundary layer

    Författare :Jens H. M. Fransson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Asymptotic suction boundary layer; Laminar-turbulent transition; Tollmien-Schlichting waves; Free stream turbulence; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : .... LÄS MER

  4. 18. 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

  5. 19. Conceptual Design of Propulsion Systems for Boundary Layer Ingestion

    Författare :Sebastian Samuelsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbo-electric aircraft; performance modeling; Aviation; boundary layer ingestion; aircraft engine; conceptual design; propulsion integration;

    Sammanfattning : To reduce the climate impact of aviation new aircraft and engine concepts as well as improved design methods are needed. In this thesis, two fronts are explored. The first concerns improved methods for the conceptual design of the engine. LÄS MER

  7. 20. 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