Search for dissertations about: "bypass engines"

Showing result 1 - 5 of 19 swedish dissertations containing the words bypass engines.

2. 1. Towards Environmentally Friendly Aero Engines

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

   Abstract : 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. READ MORE

4. 2. On the Analysis of Energy Efficient Aircraft Engines

   Author : Oskar Thulin; 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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Performance modelling; Aero engine; Turbofan; Aircraft engine; Installed propulsion; Ultra high bypass ratio; Exergy analysis; Engine weight estimate; Variable area fan nozzle; Multiple pivoting flaps; Translating cowls;

   Abstract : 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 laws of thermodynamics, it is possible to understand how the performance parameters affect the component performance, but it is difficult to directly compare the magnitude of various loss sources. READ MORE

5. 3. Aerodynamic Design and Experimental Investigation of Short Nacelles for Future Turbofan Engines

   Author : Vinícius Tavares Silva; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultra-high-bypass turbofan; Computational Fluid Dynamics; powered nacelle.; Ultra-short nacelles; experimental; thrust-and-drag bookkeeping;

   Abstract : To achieve a higher propulsive efficiency, and hence reduced fuel burn and emissions, the next generation turbofan engines are expected to have higher bypass ratios and lower fan pressure ratios. However, the larger the bypass ratio, the larger becomes the fan and thus the nacelle. The result is an undesired increase in weight and nacelle drag. READ MORE

6. 4. Divided Exhaust Period on Heavy-Duty Diesel Engines

   Author : Stefan Gundmalm; Hans-Erik Ångström; Fredrik Ekström; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : Due to growing concerns regarding global energy security and environmental sustainability it is becoming increasingly important to increase the energy efficiency of the transport sector. The internal combustion engine will probably continue to be the main propulsion system for road transportation for many years to come. READ MORE

7. 5. Aviation and the Environment- Evaluation of High Propulsive Efficiency Engines

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

   Abstract : 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. READ MORE