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Recent Progress in Aircraft Noise Research
Date: October 16, 2007, 11 a.m. to 12:30 p.m. *Please note date change
Presented By: Dr. Edmane Envia (NASA Glenn Research Center) and
Dr. Russell Thomas (NASA Langley Research Center)
Advances in aircraft noise research can be attributed to the development
of new technologies and sustained collaboration with industry,
universities and government organizations. Emphasis has been given to
developing noise prediction methods, diagnostic methods for determining
noise sources, and noise reduction methods that are applicable across a
wide range of aircraft.
Many of the current noise prediction methods are based on empirical
correlations. Procedures that link CFD and acoustic analogy methods
have improved noise prediction methods for aircraft and engine
components that are responsible for noise that impacts communities near
airports. Examples will be given that demonstrate the current
capability to predict changes in noise spectra due to changes in design
features for aircraft components.
Significant advances have also been made in experimental methods that
help identify the dominant noise sources. They include phased microphone
arrays, time dependent particle image velocimetry (PIV), and fundamental
experiments that correlate fluctuating near field pressure, temperature
and density with far field sound pressure levels. Examples will be
given for flap, slat, landing gear, jet, and fan noise sources.
Finally, significant noise reduction has been achieved with the
combination of design features of aircraft components and cycle
selection of the engines. Based on existing model data, NASA projects a
step change in the reduction of aircraft noise is possible by
introducing Ultra-High Bypass (UHB) ratio engines on either conventional
“tube and wing” configurations or integrating them into “hybrid wing”
vehicles such as the Blended Wing Body. Adding noise reduction features
to both the engine and the airframe will provide further noise
reduction. Estimates for potential noise reduction will be given for
future small twin aircraft (B737/A320 replacement). Challenges remain
to integrate the technologies in a way that lower noise, lower emissions
and improved performance (lower aircraft fuel burn). Some of these
technologies will be developed in the Subsonic Fixed Wing project of the
Fundamental Aeronautics program.
+ See Full Technical Seminar Series Schedule
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