Sökning: "Jonathan Morrison"

Hittade 2 avhandlingar innehållade orden Jonathan Morrison.

  1. 1. Effects of free-stream turbulence and three-dimensional roughness on boundary layer transition

    Författare :Santhosh Babu Mamidala; Jens H. M. Fransson; Bengt E. G. Fallenius; Jonathan Morrison; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary-layer transition; intermittency; free-stream turbulence; electret microphones; isolated roughness; sinuous instability; varicose instability; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : External disturbances such as free-stream turbulence (FST), and isolated three-dimensional roughness are strong disturbance sources to the laminar boundary layers (BLs), which can lead to a rapid transition to turbulence. The transition process eventuates to increase in skin-friction coefficient and heat transfer rate and hence, both of the aforementioned disturbance sources have practical importance. LÄS MER

  3. 2. 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