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Showing result 16 - 20 of 43 swedish dissertations matching the above criteria.

2. 16. Large Eddy Simulation for the Analysis of Supersonic Jet Noise Suppression Devices

   Author : Markus Olander Burak; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluidic injection; mixer-ejector; jet noise; Kirchhoff; forward flight effects; LES; acoustic liner; supersonic turbulent jets; broadband time-domain impedance boundary condition; chevrons; shock-associated noise; CAA; aeroacoustics;

   Abstract : Stricter noise regulations for commercial and military aircraft have increased interest in noise reduction techniques within the aerospace industry. To meet the requirements, new noise suppression technologies have to be developed and numerical methods need to be validated and possibly improved for the correct assessment of these technologies. READ MORE

4. 17. The Prometheus Complex : Striving for competence

   Author : Renée Perrin-Wallqvist; Institutionen för psykologi; []
   Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Childhood; Fire setting; Adolescence; Psychology; Development psychology; Psykologi; Utvecklingspsykologi; Psykologi;

   Abstract : The purpose of the present investigations was to obtain a more comprehensive view of fire setting by children and adolescents; to explore the prevalence of the phenomenon; whether or not it experimentally may be related to frustration or boredom and to examine the role of personality traits such as optimism, pessimism and creativity. This dissertation consists of two experimental and two interview studies. READ MORE

5. 18. Augmenting L1 Adaptive Control of Piecewise Constant Type to Aerial Vehicles

   Author : Anders Pettersson; Institutionen för reglerteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : In aerial vehicle control design, the industrial baseline is to use robust control methods together with gain-scheduling to cover the full airspeed and altitude flight envelope. An adaptive controller could possibly add value by increasing performance while keeping robustness to deviation from nominal assumptions. READ MORE

6. 19. Decompression strain during long-duration, high-altitude exposures : Effects of intermittent excursions to moderate altitude and inspired fractions of oxygen

   Author : Rickard Ånell; Ola Eiken; Mikael Gennser; Mikael Grönkvist; Ole Hyldegaard; KTH; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Teknik och hälsa; Technology and Health;

   Abstract : Today´s tactical demands and new technical solutions in fighter aircraft entail longer exposure periods at higher altitudes than before. A low cabin pressure protects pilots from pulmonary barotrauma in case of a sudden loss of cabin pressure, however it can also generate a supersaturation of nitrogen (N2) in the tissues, increasing the risks of bubble formation and decompression sickness (DCS). READ MORE

7. 20. On magnetic amplifiers in aircraft applications

   Author : Lars Austrin; Göran Engdahl; Lars Liljestrand; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; magnetic amplifier magamp ; amorphous; power losses; control winding; self-saturating; hysteresis; converter; more electric aircraft MEA ; inverter; power-by-wire; dymola; permanent magnet generator; PM-generator transformer rectifier unit TRU ; constant speed drive CSD ; excess losses or anomalous losses; modeling; simulation; unmanned aerial vehicle UAV ; Electrical engineering; Elektroteknik;

   Abstract : In the process of designing an electric power supply system for an aircraft, parameters like low weight and low losses are important. Reliability, robustness and low cost are other important factors. READ MORE