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Visar resultat 1 - 5 av 8 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Optimization and Model Validation of Transonic Compressors

   Författare :Lars R Ellbrant; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; compressor; optimization; design; metamodels; CFD; validation; multiobjective;

   Sammanfattning : Economical aspects such as reduced specific fuel consumptions and ever growing environmental requirements on emissions and percieved noise levels, are the major drivers in the search for improvement of aircraft engines. For turbofan engines, the global trend is towards higher efficiency which is accomplished by increasing component efficiencies, the bypass ratio and overall pressure ratio while keeping the engine weight low. LÄS MER

3. 2. Hydro-mechanical optimization of a wave energy converter

   Författare :Chisom Miriam Ekweoba; Andrej Savin; Halvar Gravråkmo; Uppsala universitet; []
   Nyckelord :Ballast optimization; analytical model; pitching wave energy converter; power absorption performance; wave energy converter; geometry optimization; genetic algorithm; floating platform; extended degrees of freedom; beam model; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Wave energy conversion technology has gained popularity due to its potential to be-come one of the most preferred energy sources. Its high energy density and low car-bon footprint have inspired the development of many wave energy converter (WEC) technologies, few of which have made their way to commercialisation, and many are progressing. LÄS MER

4. 3. On the Design of Energy Efficient Aero Engines: Some Recent Innovations

   Författare :Rickard Avellan; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbofan; aero engine; inter-turbine reheat; emissions; variable cycle; energy efficiency; propeller; NOx; MDO;

   Sammanfattning : In the light of the energy crisis of the 1970s, the old aerospace paradigm of flying higher and faster shifted towards the development of more energy efficient air transport solutions. Today, the aeronautical research and development community is more prone to search for innovative solutions, in particular since the improvement rate of change is decelerating somewhat in terms of energy efficiency, which still is far from any physical limits of aero engine and aircraft design. LÄS MER

5. 4. Sound for Multisensory Motion Simulators

   Författare :Alexander Väljamäe; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; auditory scene synthesis; spatial audio; presence; virtual reality; cognitive acoustics; illusory self-motion; vection ; multisensory optimization;

   Sammanfattning : Interaction in a virtual reality environment often implies situations of illusory self-motion, like, for example, in flight or driving scenarios. Striving for pictorial realism, currently available motion simulators often exhibit relatively poor sound design. LÄS MER

7. 5. Improved remaining useful life estimations for on-condition parts in aircraft engines

   Författare :Veronica Fornlöf; Anna Syberfeldt; Anders Skoogh; Högskolan i Skövde; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aircraft engine maintenance; Reliability; Remaining useful life; On-condition parts; Prognosis; Technology; Teknik; Production and Automation Engineering; Produktion och automatiseringsteknik;

   Sammanfattning : This thesis focuses on obtaining better estimates of remaining life for on-condition (OC) parts in aircraft engines. Aircraft engine components are commonly classified into three categories, life-limited parts (LLP), OC-parts and consumables. Engine maintenance typi-cally accounts for 10% to 20% of aircraft-related operating cost. LÄS MER