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Accession Number N20120010350
Title Aeroacoustic Study of a High-Fidelity Aircraft Model, Part 2.
Publication Date Jun 2012
Media Count 22p
Personal Author D. H. Neuhart M. R. Khorrami
Abstract In this paper, we present unsteady surface pressure measurements for an 18%-scale, semi-span Gulfstream aircraft model. This high-fidelity model is being used to perform detailed studies of airframe noise associated with main landing gear, flap components, and gear-flap interaction noise, as well as to evaluate novel noise reduction concepts. The aerodynamic segment of the tests, conducted in the NASA Langley Research Center 14- by 22-Foot Subsonic Tunnel, was completed in November 2010. To discern the characteristics of the surface pressure fluctuations in the vicinity of the prominent noise sources, unsteady sensors were installed on the inboard and outboard flap edges, and on the main gear wheels, struts, and door. Various configurations were tested, including flap deflections of 0., 20., and 39., with and without the main landing gear. The majority of unsteady surface pressure measurements were acquired for the nominal landing configuration where the main gear was deployed and the flap was deflected 39.. To assess the Mach number variation of the surface pressure amplitudes, measurements were obtained at Mach numbers of 0.16, 0.20, and 0.24. Comparison of the unsteady surface pressures with the main gear on and off shows significant interaction between the gear wake and the inboard flap edge, resulting in higher amplitude fluctuations when the gear is present.
Keywords Aeroacoustics
Aerodynamic noise
Aircraft noise
Civil aviation
General aviation aircraft
Landing gear
Mach number
Noise reduction
Pressure measurement
Pressure oscillations
Subsonic wind tunnels
Wind tunnel tests

Source Agency National Aeronautics and Space Administration
NTIS Subject Category 46A - Acoustics
51A - Aerodynamics
Corporate Author National Aeronautics and Space Administration, Hampton, VA. Langley Research Center.
Document Type Conference proceedings
Title Note N/A
NTIS Issue Number 1226
Contract Number N/A

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