Search for dissertations about: "h M"

Showing result 21 - 25 of 381 swedish dissertations containing the words h M.

2. 21. Understanding processes and travel behaviour changes connected to electric vehicle adoption

   Author : Joram H.M. Langbroek; Joel P. Franklin; Yusak Susilo; Jilian Anable; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transportvetenskap; Transport Science;

   Abstract : The use of electric vehicles (EVs) has the potential to increase the sustainability of the transport system, especially in case of unchanged or decreased car use, eco-driving and charging during hours of low electricity demand in case of an electricity generation mix with a large share of renewable energy sources. However, EVs still use much energy and EV-use does not solve problems regarding accessibility, social equity, traffic safety and has only a limited beneficial effect on liveability (e. READ MORE

4. 22. Nanofabrication of Diffractive Soft X-ray Optics

   Author : Magnus Lindblom; Hans M. Hertz; Erik H. Anderson; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nanofabrication; Zone plate; x-ray; diffractive x-ray optics; x-ray microscopy; Optics; Optik; Physics; Fysik;

   Abstract : This thesis summarizes the present status of the nanofabrication of diffractive optics, i.e. zone plates, and test objects for soft x-ray microscopy at KTH. The emphasis is on new and improved fabrication processes for nickel and germanium zone plates. READ MORE

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

   Author : Santhosh Babu Mamidala; Jens H. M. Fransson; Bengt E. G. Fallenius; Jonathan Morrison; KTH; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 24. Attenuation of boundary layer disturbances by means of streamwise vortices

   Author : Sohrab Sattarzadeh Shirvan; Jens H. M. Fransson; Valery Chernoray; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer stability; Tollmien-Schlichting waves; oblique waves; transition to turbulence; streamwise vortices; miniature vortex generators; instability control; drag reduction;

   Abstract : The stability of the boundary layer developed on a flat plate is studied in the presence of streamwise streaks where disturbances of different types are introduced in the wall-bounded shear layer. The experimental investigations are aimed at flow control by means of passively damping the energy growth of the disturbances in the streaky boundary layer and furthermore delay the onset of the transition in the streamwise direction. READ MORE

7. 25. Boundary layer streaks as a novel laminar flow control method

   Author : Sohrab Sattarzadeh Shirvan; Jens H. M. Fransson; Edward B. White; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer stability; laminar to turbulent transition; laminar flow control; drag reduction; Tollmien-Schlichting waves; oblique waves; streaky boundary layers; miniature vortex generators; discrete suction;

   Abstract : A novel laminar flow control based on generation of spanwise mean velocity gradients (SVG) in a flat plate boundary layer is investigated where disturbances of different types are introduced in the wall-bounded shear layer. The experimental investigations are aimed at; (i) generating stable and steady streamwise streaks in the boundary layer which set up spanwise gradients in the mean flow, and (ii) attenuating disturbance energy growth in the streaky boundary layers and hence delaying the onset of turbulence transition. READ MORE