Search for dissertations about: "Aerospace Engineering"

Showing result 11 - 15 of 337 swedish dissertations containing the words Aerospace Engineering.

2. 11. Optimization of Vehicle Structures under Uncertainties

   Author : Sandeep Shetty; Larsgunnar Nilsson; Kaj Fredin; Alexander Govik; Mårten Olsson; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : Advancements in simulation tools and computer power have made it possible to incorporate simulation-based structural optimization in the automotive product development process. However, deterministic optimization without considering uncertainties such as variations in material properties, geometry or loading conditions might result in unreliable optimum designs. READ MORE

4. 12. Buffer Related Dispersive Effects in Microwave GaN HEMTs

   Author : Johan Bergsten; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; trapping effects; C-doping; AlGaN GaN interface quality; recessed ohmic contacts; GaN HEMT; buffer design;

   Abstract : In applications such as mobile communication and radar, microwave power generation at high frequency is of utmost importance. The GaN HEMT offers a unique set of properties that makes it suitable for high power amplification at high frequencies. READ MORE

5. 13. Sense, Actuate and Survive : Ceramic Microsystems for High-Temperature Aerospace Applications

   Author : Peter Sturesson; Greger Thornell; Lena Klintberg; Peter Bull; Pelle Rangsten; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High temperature; ceramics; microsystems; aerospace; sensors; thrusters; Teknisk fysik med inriktning mot mikrosystemteknik; Engineering Science with specialization in Microsystems Technology; Försvarssystem;

   Abstract : In aerospace applications, but also in manufacturing, mining, energy industry and natural hazards, high temperature, corrosion, erosion and radiation, challenge the performance and being of hardware.In this work, high-temperature co-fired ceramic (HTCC) alumina and platinum have been used for a range of devices intended for aerospace applications at up to 1000°C. READ MORE

6. 14. Large-eddy simulation on the effects of fuel injection pressure on gasoline spray characteristics

   Author : Sandip Wadekar; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High pressure fuel-injection; GDI engine; LES; Spray characteristics;

   Abstract : Increasing the injection pressure in gasoline direct injection engines has a substantial potential to reduce emissions while maintaining high efficiency in spark ignition engines. Present gasoline injectors operate at pressures of 20 to 30 MPa. READ MORE

7. 15. Design and analysis of a fault-tolerant fractional slot PMSM for a vehicle application

   Author : Christian Dubar; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Saturation; Permanentmagnet synchronousmachine PMSM ; Fault-tolerance; windings; Concentrated; Fractional slot; Unbalanced operation;

   Abstract : The permanent magnet synchronous motor (PMSM) is an interesting alternative for an electric motor drive system in automotive applications, due to to the high efficiency requirement; as only a limited amount of energy can be stored in the relatively expensive battery. Another advantage is the high torque and power density a PMSM can achieve since it is very important to save especially space but also weight in vehicle applications. READ MORE