Search for dissertations about: "Jens Fransson"

Showing result 1 - 5 of 21 swedish dissertations containing the words Jens Fransson.

2. 1. Wakes behind wind turbines - Studies on tip vortex evolution and stability

   Author : Ylva Odemark; Jens Fransson; Jens Madsen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind power; aerodynamics; hot-wire anemometry; vortex dynamics;

   Abstract : The increased fatigue loads and decreased power output of a wind turbine placed in the wake of another turbine is a well-known problem when building new wind power farms. In order to better estimate the total power output of a wind power farm, knowledge about the development and stability of wind turbine wakes is crucial. READ MORE

4. 2. Investigations of the asymptotic suction boundary layer

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

   Abstract : .... READ MORE

5. 3. Experimental Investigation of Performance, Flow Interactions and Rotor Forcing in Axial Partial Admission Turbines

   Author : Jens Fridh; Torsten Fransson; Björn Laumert; Jürgen Seume; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; axial turbine; partial admission; part loads; experimental investigation; turbine performance; losses; dynamic rotor forces; forced response; unsteady flow; axialturbin; partialpådrag; dellaster; reglersteg; experimentell undersökning; turbinprestanda; förluster; dynamiska krafter; rotorvibration; instationär strömning;

   Abstract : The thesis comprises a collection of four papers with preceding summary and supplementary appendices. The core investigation solely is of experimental nature although reference and comparisons with numerical models will be addressed. READ MORE

6. 4. Flow control of boundary lagers and wakes

   Author : Jens H. M. Fransson; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laminar-turbulent transition; asymptotic suction boundary layer; free stream turbulence; Tollmien-Schlichting wave; stability; flow control; cylinder wake; Engineering mechanics; Teknisk mekanik;

   Abstract : Both experimental and theoretical studies have beenconsidered on flat plate boundary layers as well as on wakesbehind porous cylinders. The main thread in this work iscontrol, which is applied passively and actively on boundarylayers in order to inhibit or postpone transition toturbulence; and actively through the cylinder surface in orderto effect the wakecharacteristics. READ MORE

7. 5. The Frequency of Supernovae in the Early Universe

   Author : Jens Melinder; Claes Fransson; Enrico Cappellaro; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; supernovae; supernova typing; supernova rates; photometric redshifts; Lyman Break Galaxies; Astronomy; Astronomi; Astronomy; astronomi;

   Abstract : Supernovae are cosmic explosions of cataclysmic proportion that signify the death of a star. While being interesting phenomena in their own right, their brightness also make them excellent probes of the early universe. Depending on the type of the progenitor star and the origin of the explosion different subjects can be investigated. READ MORE