Sökning: "KTH 2016"

Visar resultat 16 - 20 av 445 avhandlingar innehållade orden KTH 2016.

1. 16. Numerical studies on flows with secondary motion

   Författare :Jacopo Canton; Philipp Schlatter; David Moxey; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear dynamical systems; instability; bifurcation; flow control; skin-friction reduction; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : This work is concerned with the study of flow stability and turbulence control - two old but still open problems of fluid mechanics. The topics are distinct and are (currently) approached from different directions and with different strategies. LÄS MER

3. 17. Extreme Implementations of Wide-Bandgap Semiconductors in Power Electronics

   Författare :Juan Colmenares; Hans-Peter Nee; Leon M. Tolbert; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cryogenic; Gallium Nitride; Gate Driver; Harsh Environments; High Efficiency Converter; High Temperature; MOSFETs; Normally- ON JFETs; Reliability; Silicon Carbide; Wide-Band Gap Semiconductors; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Wide-bandgap (WBG) semiconductor materials such as silicon carbide (SiC) and gallium-nitride (GaN) allow higher voltage ratings, lower on-state voltage drops, higher switching frequencies, and higher maximum temperatures. All these advantages make them an attractive choice when high-power density and high-efficiency converters are targeted. LÄS MER

4. 18. Resource management for network-assisted D2D communication

   Författare :Demia Della Penda; Mikael Johansson; Emil Björnson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : During the last decade, the widespread use of smart devices and mobile applications has led to a massive growth of the mobile traffic demand. Efficiency and scalability are therefore key criteria for the development of future cellular systems, in which device-to-device (D2D) communication is recognized as one of the promising technologies. LÄS MER

5. 19. Internal Erosion Phenomena in Embankment Dams : Throughflow and internal erosion mechanisms

   Författare :Farzad Ferdos; Anders Wörman; Bijan Dargahi; Fredrik Johansson; Willi Hager; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Internal erosion modelling in porous material; Constitutive law of erosion for closure of continuum-mechanics-based balance equations for numerical modelling; High Reynolds-number turbulent flow; Flow laws; Coarse rockfill material throughflow; Computational Fluid Dynamics.; Civil and Architectural Engineering; Byggvetenskap;

   Sammanfattning :  In this study, two major internal erosion initiation processes, suffusion and concentrated leak mechanisms, which lead to both defect formation in a dam’s body and its foundation and high throughflow in dams subjected to internal erosion were studied. This understanding has the potential to facilitate numerical modelling and expedite dam safety assessment studies. LÄS MER

7. 20. Sustainable Energy Access for All : Initial tools to compare technology options and costs

   Författare :Francesco Fuso Nerini; Mark Howells; Hisham Zerriffi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energiteknik; Energy Technology;

   Sammanfattning : This thesis presents analytical advances to support quantitative insights into national and local policies for achieving energy access goals. The key objective is the creation of an analytical tool to compare technology options for achieving energy access goals and to estimate the cost of reaching those goals. LÄS MER