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Assessment at full scale of nozzle/wing geometry effects on OTW aeroacoustic characteristicsThe effects on acoustic characteristics of nozzle type and location on a wing for STOL engine over-the-wing configurations are assessed at full scale on the basis of model-scale data. Three types of nozzle configurations are evaluated: a circular nozzle with external deflector mounted above the wing, a slot nozzle with external deflector mounted on the wing and a slot nozzle mounted on the wing. Nozzle exhaust plane locations with respect to the wing leading edge are varied from 10 to 46 percent chord (flaps retracted) with flap angles of 20 deg (take-off attitude) and 60 deg (approach attitude). Perceived noise levels (PNL) are calculated as a function of flyover distance at 152 m altitude. From these plots, static EPNL values, defined as flyover relative noise levels, are calculated and plotted as a function of lift and thrust ratios. From such plots the acoustic benefits attributable to variations in nozzle/deflector/wing geometry at full scale are assessed for equal aerodynamic performance.
Document ID
19790055789
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Groesbeck, D.
(NASA Lewis Research Center Cleveland, OH, United States)
Von Glahn, U.
(NASA Lewis Research Center Cleveland, Ohio, United States)
Date Acquired
August 9, 2013
Publication Date
June 1, 1979
Subject Category
Acoustics
Meeting Information
Meeting: Acoustical Society of America, Meeting
Location: Cambridge, MA
Start Date: June 11, 1979
End Date: June 15, 1979
Sponsors: Acoustical Society of America
Accession Number
79A39802
Distribution Limits
Public
Copyright
Other

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