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Accession Number N20120010228
Title Investigation of Twin Jet Aeroacoustic Properties in the Presence of a Hybrid Wing Body Shield.
Publication Date Jun 2012
Media Count 24p
Personal Author M. J. Doty
Abstract In preparation for upcoming wind tunnel acoustic experiments of a Hybrid Wing Body (HWB) vehicle with two jet engine simulator units, a series of twin jet aeroacoustic investigations were conducted leading to increased understanding and risk mitigation. A previously existing twin jet nozzle system and a fabricated HWB aft deck fuselage are combined for a 1.9% model scale study of jet nozzle spacing and jet cant angle effects, elevon deflection into the jet plume, and acoustic shielding by the fuselage body. Linear and phased array microphone measurements are made, and data processing includes the use of DAMAS (Deconvolution Approach for the Mapping of Acoustic Sources). Closely-spaced twin jets with a 5 inward cant angle exhibit reduced noise levels compared to their parallel flow counterparts at similar and larger nozzle spacings. A 40 elevon deflection into the twin jet plume, which is required for HWB ground rotation, can significantly increase upstream noise levels (more than 5 dB OASPL) with only minimal increases in the downstream direction. Lastly, DAMAS processing can successfully measure the noise source distribution of multiple shielded jet sources.
Keywords Aeroacoustics
Body-wing configurations
Jet engines
Noise intensity
Nozzle design
Nozzle inserts
Wind tunnel apparatus
Wind tunnel tests
Wind tunnels

Source Agency National Aeronautics and Space Administration
NTIS Subject Category 51C - Aircraft
51F - Test Facilities & Equipment
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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