Sökning: "step width"

Visar resultat 11 - 15 av 61 avhandlingar innehållade orden step width.

  1. 11. Wind turbine simulations using spectral elements

    Författare :Elektra Kleusberg; Dan Henningson; Philipp Schlatter; Stefan Ivanell; Johan Meyers; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind turbine; wakes; wake interaction; computational fluid dynamics; actuator line method; spectral elements; free-stream turbulence; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : Understanding the flow around wind turbines is a highly relevant research question due to the increased interest in harvesting energy from renewable sources. This thesis approaches the topic by means of numerical simulations using the actuator line method and the incompressible Navier–Stokes equations in the spectral element code Nek5000. LÄS MER

  3. 12. GaN/AlN Multiple Quantum Well Structures

    Författare :Xinju Liu; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; GaN; AlN; multiple quantum well; Molecular beam epitaxy; Si 111 ; intersubband transition; sapphire; GaN template;

    Sammanfattning : The III-nitride semiconductors: InN, GaN and AlN are promising for photonic, high power and high temperature electronic devices. Their large and direct band gaps cover the range 0.7 to 6.2 eV, i. LÄS MER

  4. 13. Experimental Results of a Load-Controlled Vertical Axis Marine Current Energy Converter

    Författare :Johan Forslund; Mats Leijon; Karin Thomas; Jan Sundberg; Tom Blackmore; Uppsala universitet; []
    Nyckelord :Marine Current; Vertical Axis; Load Control; ; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : This thesis investigates the load control of a marine current energy converter using a vertical axis turbine mounted on a permanent magnet synchronous generator. The purpose of this thesis is to show the work done in the so far relatively uncharted territory of control systems for hydro kinetic energy conversion. LÄS MER

  5. 14. Growth of 3C-SiC and Graphene for Solar Water-Splitting Application

    Författare :Yuchen Shi; Jianwu W. Sun; Rositsa Yakimova; Mikael Syväjärvi; Gholamreza Yazdi; Didier Chaussende; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Silicon carbide (SiC) is regarded as an important semiconductor for a variety of applications including high-temperature, high-power and high-frequency devices. The most common polytypes of SiC are hexagonal (4H- or 6H-SiC) and cubic silicon carbide (3C-SiC), which differ from each other by the ordering of the Si–C bilayers along the c-axis crystal direction. LÄS MER

  7. 15. Mechanical and Electrical Properties of Mesoscopic Wires

    Författare :Sara Blom; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Rabi oscillations; conductance quantization; free electron model; mesoscopic; microwave; channel; force fluctuations; adiabatic; nanowire;

    Sammanfattning : The mechanical and electrical properties of mesoscopic wires have been studied theoretically using a free electron model. When a mesoscopic wire is elongated the conductance decreases in steps. Each step is accompanied by an abrupt change in the force. LÄS MER