Sökning: "Aerospace Engineering"

Visar resultat 16 - 20 av 339 avhandlingar innehållade orden Aerospace Engineering.

1. 16. Energy Harvesting for Wireless and Less-Wired Sensors in Gas Turbines

   Författare :Elof Köhler; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; coupled harvester; piezoelectric harvester; piezoelectric; Energy harvester; thermoelectric harvester; harsh environment; thermoelectric; self-tuning;

   Sammanfattning : Four types of energy harvesters aimed for gas turbine applications were developed during this thesis. The unique gas turbine environment shaped the design- and material choices. A semiconductor thermoelectric harvester was built for a location in the gas turbine with active cooling at 600°C, with 800°C wall temperature. LÄS MER

3. 17. Aerodynamic Investigation of Leading Edge Contouring and External Cooling on a Transonic Turbine Vane

   Författare :Ranjan Saha; Torsten Fransson; Jens Fridh; Tony Arts; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gas turbine; aerodynamics; secondary flow; external cooling; trailing edge cooling; film cooling; aerodynamic loss; high pressure turbine; nozzle guide vane; Aerospace Engineering; Flyg- och rymdteknik; Energiteknik; Energy Technology;

   Sammanfattning : Efficiency improvement in turbomachines is an important aspect in reducing the use of fossil-based fuel and thereby reducing carbon dioxide emissions in order to achieve a sustainable future. Gas turbines are mainly fossil-based turbomachines powering aviation and land-based power plants. LÄS MER

4. 18. Direct Write Technology of SIN Tunnel Junctions for Thermometry and Microwave Devices

   Författare :Ernst Otto; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; Cold-Electron Bolometer; direct write technology; SIN tunnel junction;

   Sammanfattning : This thesis concerns development of SIN junction technology for thermometry and microwave detectors, as well as technology of a planar phase switch as a part of integratedmicrowave receiver.Cold-Electron Bolometer (CEB) is a sensitive detector of a microwave radiation, in which SIN tunnel junctions are used for temperature measurement of a nanoscale absorber in thesame way as in SIN thermometers. LÄS MER

5. 19. Static and fatigue analyses of welded steel structures : some aspects towards lightweight design

   Författare :Mansoor Khurshid; Zuheir Barsoum; Lars-Erik Lindgren; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fatigue strength; welded joints; static strength; high strength steel; Farkostteknik; Vehicle and Maritime Engineering; Aerospace Engineering; Flyg- och rymdteknik;

   Sammanfattning : The objectives of this thesis comprise of overcoming the challenges in designing lightweight welded structures such as material selection, choice of fatigue design methods, and increased performance by using improvement techniques. Material selection of welded joints is dependent on the filler and base material strengths. LÄS MER

7. 20. Numerical investigation of tonal noise sources from centrifugal fan

   Författare :Martin Ottersten; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Computational Aeroacoustics; Tonal Noise; Centrifugal Fan; Blade Passing Frequency;

   Sammanfattning : Heating, ventilating, and air conditioning systems (HVAC) are today an important part of many people's life. They provide a sufficient amount of airflow with the correct temperature, quality, and humidity. The negative side is the noise it produces. Many improvements have been made in building development to reduce noise from the environment. LÄS MER