Design trade studies and assessment for advanced quiet aircraft concepts

(cont.) designed for 4,000nm range, 25,000 to 35,000ft cruise altitude, Mach 0.8 at cruise, and 10,000 to 14,000ft takeoff field length. By identifying the main high-level design drivers of an aircraft design, the mission for a baseline silent aircraft planform and engine was determined. A silent aircraft was designed for a range of 4,000nm and 250 passengers. A noise assessment was conducted on the engine and airframe noise sources of the resulting design. The noise impacts of five engine (jet, fan forward, fan rearward, core, and turbine) and airframe (airfoil, elevator, slat, drag rudder, and undercarriage) noise sources were investigated in terms of their noise footprints and, more specically, the loudest noise caused outside the airport boundary. The greatest noise source was the drag rudder, which was required to offset the idle thrust of the engine during approach. Because of the variable cycle and shielding effects on the embedded engines, engine noise at takeoff was greatly reduced. The main contribution of engine noise was the fan rearward noise. Overall, airframe and engine noise during approach was found to be 12dBA and 9dBA louder than during takeoff respectively. The loudest airframe noise occurred during a 3-degree approach, and was about 6dBA louder than engine noise.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Tan, David York Luen, 1979-

Advisor dc:contributor.advisor

• Karen E. Willcox.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/27863

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/27863