Sökning: "Aircraft noise"

Visar resultat 16 - 20 av 60 avhandlingar innehållade orden Aircraft noise.

1. 16. 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. 17. 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

4. 18. Linear Quadratic Gaussian Controllers for Feedforward Active Noise Control : Pushing Performance and Moving Towards Adaptive Control

   Författare :Annea Barkefors; Mikael Sternad; Anders Ahlén; Lars-Johan Brännmark; Bengt Carlsson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active noise control; ANC; LQG; feedforward control; sound field control; Elektroteknik med inriktning mot reglerteknik; Electrical Engineering with specialization in Automatic Control;

   Sammanfattning : Active noise control is a research area focused on using destructive interference of sound fields to attenuate undesired noise. Methods for active noise control are best suited for low frequency noise, as the complexity of the problem grows rapidly with frequency. LÄS MER

5. 19. On the use of liners to reduce aircraft jet engine noise

   Författare :Tamer Elnady; KTH; []
   Nyckelord :;

   Sammanfattning : .... LÄS MER

7. 20. Active Noise Control of Enclosed Sound Fields Optimising the Performance

   Författare :Per Sjösten; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; optimising actuator and sensor positions; hybrid controller for anc; fast feedforward algorithm; multiple-error algorithm; active noise control; complex lms; multichannel feedforward algorithm; simulated annealing; mean-field annealing; multiple-reference controller;

   Sammanfattning : Active noise control is the art of reducing a primary unwanted sound field by interference with an actively created secondary sound field. To achieve high reduction, it is crucial to obtain both temporal and spatial matching between the primary and the secondary sound fields. LÄS MER