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Visar resultat 1 - 5 av 32 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Towards Environmentally Friendly Aero Engines

   Författare :Rickard Avellan; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; geared turbofan; energy efficiency; turbofan; environmentally friendly; DDTF; aero engines; GTF; aircraft;

   Sammanfattning : Since the introduction of subsonic jet driven commercial aircraft, incremental improvements in overall efficiency has been a driving requirement as well as a selling argument for the engine industry. The historical overall efficiency improvement is the result of continuous advances in aerodynamic design, increase of overall pressure ratios, turbine inlet temperatures and propulsive efficiencies in parallel with the development of stronger and lighter materials. LÄS MER

3. 2. Analysis of concepts to reduce the environmental impact of aviation

   Författare :Linda Larsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turboprop; Contrails; Turbofan; Aviation; Open rotor; Aircraft engine; Environment;

   Sammanfattning : The average yearly increase in passenger kilometres travelled by air has been 5.8 % over the last 40 years. Fortunately the fuel consumption has not increased at the same rate. Over the same time period the average increase in fuel sold has been 2. LÄS MER

4. 3. Aviation and the Environment- Evaluation of High Propulsive Efficiency Engines

   Författare :Linda Larsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aircraft engine; Environment; Open rotor; Turbofan; Aviation;

   Sammanfattning : There has been more than a tenfold increase in passenger kilometers traveled over the last 40 years. The highest rate of growth today is in developing countries such as China and India. These countries also have the two largest populations in the world. LÄS MER

5. 4. Multi-Disciplinary Conceptual Design of Future Jet Engine Systems

   Författare :Konstantinos G. Kyprianidis; Stephen O. T. Ogaji; Riti Singh; Herbert Saravanmuttoo; UK Cranfield University; []
   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; Gas Turbine; Intercooled; Recuperated; Turbofan; Future; Simulation; Performance; Aircraft; Emissions; Multi-disciplinary; Jet Engine; Energy- and Environmental Engineering; energi- och miljöteknik;

   Sammanfattning : This thesis describes various aspects of the development of a multi-disciplinary aero engine conceptual design tool, TERA2020 (Techno-economic, Environmental and Risk Assessment for 2020), based on an explicit algorithm that considers: engine performance, engine aerodynamic and mechanical design, aircraft design and performance, emissions prediction and environmental impact, engine and airframe noise, and production, maintenance and direct operating costs.As part of this research effort, a newly-derived semi-empirical NOx correlation for modern rich-burn single-annular combustors is proposed. LÄS MER

7. 5. On Exergy and Aero Engine Applications

   Författare :Oskar Thulin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Installed propulsion unit performance; Turbofan; Aero engine; Performance modelling; Exergy analysis;

   Sammanfattning : Aero engine performance analysis is highly multidimensional using various measures of component performance such as turbomachinery and mechanical efficiencies, and pressure loss coefficients. Using conventional performance analysis, relying on only the first law of thermodynamics, it is possible to understand how the performance parameters affect the component performance, but not how the component performance relates to the system performance. LÄS MER