Aviation and the Environment- Evaluation of High Propulsive Efficiency Engines

Licentiate thesis, 2012

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. If the economy in these countries continues to grow at the expected rate they will soon come to dominate air traffic and be a major contributor to the continued increase in traffic. With this foreseen growth the question of how to reduce the effect of aviation on the environment is very important. The development of more efficient aircraft and engines is one of the reasons that emissions from air traffic has not increased at the same rate as air traffic itself. Further development of fue efficient engines and aircraft is thus needed in order to reach the target of a sustainable society with aviation. In this thesis some alternative high propulsive efficiency concepts are evaluated. These configurations are; the high bypass ratio turbofan, the geared turbofan and the open rotor. Several aspects of these concepts are discussed in the light of different design targets. Although issues such as noise, technology readiness and cost are discussed, the main objective has been to evaluate their potential for reducing fuel consumption. An overview is also given of some of the most important considerations when discussing future aviation, such as aviations contribution to global warming, noise around airports and factors affecting fuel consumption.