Sökning: "wind direction"

Visar resultat 21 - 25 av 84 avhandlingar innehållade orden wind direction.

1. 21. Analysis of the Unsteady Flow Field of a Passenger Vehicle

   Författare :Lennert Sterken; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind tunnel; Wake; CFD; Pressure measurements; Extensions; Yaw response; External aerodynamics; Aerodynamic forces;

   Sammanfattning : Political legislation and consumer requirements for a sustainable society require that vehicle manufacturers focus on reduced fuel consumption and lower emissions. Areduction in the overall energy consumption can be directly linked to a decrease of the driving resistance, where the aerodynamic drag significantly contributes at velocities above 70km/h. LÄS MER

3. 22. Distributed Control of HVDC Transmission Grids

   Författare :Davood Babazadeh; Lars Nordström; Oriol Gomis; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; co-simulation; cyber-physical system; DC slack bus; distributed control; HVDC grids; power injection; topology processor; wind farms; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Recent issues such as priority access of renewable resources recommended by European energy directives and increase the electricity trading among countries lead to new requirements on the operation and expansion of transmission grids. Since AC grid expansions are limited by legislative issues and long distance transmission capacity, there is a considerable attention drawn to application of HVDC transmission grids on top of, or in complement to, existing AC power systems. LÄS MER

4. 23. Flight Behaviour of Passerines on Nocturnal Migration

   Författare :Cecilia Nilsson; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bird migration; Passerines; Flight Behaviour; Tracking radar; Optimal migration; Flight speed; Airspeed; Wind drift; Nocturnal migration; Coastline effects; Flight directions; Reverse migration;

   Sammanfattning : Many passerines migrate during the night and at high altitudes, making their migration difficult to observe. By using tracking radars we have been able to make exact observations of the flight behaviour of passerines on nocturnal migration, which has enabled us to test several hypotheses about adaptive values and constraints regarding migratory behaviour in different ecological contexts. LÄS MER

5. 24. Dynamic Rating with Applications to Renewable Energy

   Författare :Kateryna Morozovska; Patrik Hilber; Tor Laneryd; Hans Ezz Edin; Adamantios Marinakis; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic rating; dynamic line rating; dynamic transformer rating; power transformers; power system optimization; wind farm planning; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Dynamic rating (DR) of power components is a method for assessing real-time capacity of large scale power transmission and distribution devices (commonly: transmission lines, power transformers, underground cables) and using this knowledge for adjusting loading limits of these components. Dynamic rating of power lines or dynamic line rating (DLR) is a pioneering technology in the area of dynamic rating. LÄS MER

7. 25. Instrumentation for energetic Neutral atom measurements at Mars, Venus and The Earth

   Författare :Klas Brinkfeldt; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Energetic neutral atoms; instruments and techniques; mass spectrometry; microchannel plates; solid state detectors; solar wind interaction; planets; magnetosphere; exosphere; ring current; Space physics; Rymdfysik;

   Sammanfattning : This thesis deals with the development and calibrations of sensors to measure energetic neutral atoms (ENAs) at Mars, Venus, and the Earth. ENAs are formed in charge exchange processes between energetic, singly--charged ions and a cold neutral gas. LÄS MER