Sökning: "offshore measurements"

Visar resultat 21 - 25 av 30 avhandlingar innehållade orden offshore measurements.

  1. 21. Multilevel three-phase dual active bridge dc-dc converters - A study on converter modulation, capacitive energy requirement, ZVS boundaries, MFT's winding connections, and core losses

    Författare :Babak Alikhanzadehalamdari; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-voltage power converters; dual active bridge; harmonic analysis; three-phase system; medium-frequency transformer; capacitor sizing; multilevel converters; high power-density systems; transformer winding connection; core loss modeling; dc collector network; soft-switching converters;

    Sammanfattning : The collection and transmission of power from offshore wind turbines using dc have advantages over the ac system. One of the enabling technologies for deploying dc collection is the dc-dc converter that boosts the dc output from the turbine to the medium-voltage dc level of the collection grid. LÄS MER

  3. 22. Numerical Computations of Wakes Behind Wind Farms

    Författare :Ola Eriksson; Stefan Ivanell; Simon-Philippe Breton; Anna Rutgersson; Dan Henningson; Niels Troldborg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wind turbine; Wind power; Wind farm; Wakes; Long distance wakes; Farm-Farm; Farm to farm interaction; Wind farm cluster; Large Eddy simulations; LES; Actuator disc method; ACD; CFD; Ellipsys3D;

    Sammanfattning : More and larger wind farms are planned offshore. As the most suitable build sites are limited wind farms will be constructed near to each other in so called wind farm clusters. Behind the wind turbines in these farms there is a disrupted flow of air called a wake that is characterized by reduced wind speed and increased turbulence. LÄS MER

  4. 23. MODELLING AND SIMULATION OF ELASTIC & PLASTIC BEHAVIOUR OF PROPAGATING IMPACT WAVE : Impact- echo and Explosive welding process development

    Författare :Mohammad Tabatabaee Ghomi; Jafar Mahmoudi; Golamhoosin Liaghat; Hamid Bahai; Mälardalens högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy- and Environmental Engineering; energi- och miljöteknik;

    Sammanfattning : A force that is applied dynamically in a short period of time is called an impact force (shock wave). Due to the concentrated application of force on a small area in a fraction of a second, unique applications have emerged that other types of loadings are not capable of performing. LÄS MER

  5. 24. Cooling Strategies for Wave Power Conversion Systems

    Författare :Antoine Baudoin; Cecilia Boström; Anne Blavette; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wave power; power conversion system; thermal management; power elctronics; passive cooling; natural convection.;

    Sammanfattning : The Division for Electricity of Uppsala University is developing a wave power concept. The energy of the ocean waves is harvested with wave energy converters, consisting of one buoy and one linear generator. The units are connected in a submerged substation. The mechanical design is kept as simple as possible to ensure reliability. LÄS MER

  7. 25. Toward Anti-icing and De-icing Surfaces : Effects of Surface Topography and Temperature

    Författare :Golrokh Heydari; Per Claesson; Eric Tyrode; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anti-icing; topography; supercooled water; wetting hysteresis; superhydrophobic; contact angle; nucleation; freezing delay; de-icing; ice adhesion; hydration water; liquid-like layer; smooth; lubrication; anti-is; topografi; underkylt vatten; vätningshysteres; superhydrofob; kontaktvinkel; kärnbildning; avisning; isadhesion; hydrerat vatten; vätskeliknande skikt; smörjning; Kemi; Chemistry;

    Sammanfattning : Icing severely affects society, especially in the Nordic countries. Iceaccumulation can result in critical performance problems and safetyconcerns for instance in road, air and sea transportation, transmissionlines, marine and offshore structures, wind turbines and heat exchangers. LÄS MER