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collection:
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nasa new
collection
nasa new
collection
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mediatype:
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texts
mediatype
texts
mediatype
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collection:
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nasa_techdocs
collection
nasa_techdocs
collection
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title:
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Aeroelastic Stability of a Four-Bladed Semi-Articulated Soft-Inplane Tiltrotor Model
title
Aeroelastic Stability of a Four-Bladed Semi-Articulated Soft-Inplane Tiltrotor Model
title
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description:
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A new four-bladed, semi-articulated, soft-inplane rotor system, designed as a candidate for future heavy-lift rotorcraft, was tested at model scale on the Wing and Rotor Aeroelastic Testing System (WRATS), a 1/5-size aeroelastic wind-tunnel model based on the V-22. The experimental investigation included a hover test with the model in helicopter mode subject to ground resonance conditions, and a forward flight test with the model in airplane mode subject to whirl-flutter conditions. An active control system designed to augment system damping was also tested as part of this investigation. Results of this study indicate that the new four-bladed, soft-inplane rotor system in hover has adequate damping characteristics and is stable throughout its rotor-speed envelope. However, in airplane mode it produces very low damping in the key wing beam-bending mode, and has a low whirl-flutter stability boundary with respect to airspeed. The active control system was successful in augmenting the damping of the fundamental system modes, and was found to be robust with respect to changes in rotor-speed and airspeed. Finally, conversion-mode dynamic loads were measured on the rotor and these were found to be significantly lower for the new soft-inplane hub than for the previous baseline stiff-inplane hub.
description
A new four-bladed, semi-articulated, soft-inplane rotor system, designed as a candidate for future heavy-lift rotorcraft, was tested at model scale on the Wing and Rotor Aeroelastic Testing System (WRATS), a 1/5-size aeroelastic wind-tunnel model based on the V-22. The experimental investigation included a hover test with the model in helicopter mode subject to ground resonance conditions, and a forward flight test with the model in airplane mode subject to whirl-flutter conditions. An active control system designed to augment system damping was also tested as part of this investigation. Results of this study indicate that the new four-bladed, soft-inplane rotor system in hover has adequate damping characteristics and is stable throughout its rotor-speed envelope. However, in airplane mode it produces very low damping in the key wing beam-bending mode, and has a low whirl-flutter stability boundary with respect to airspeed. The active control system was successful in augmenting the damping of the fundamental system modes, and was found to be robust with respect to changes in rotor-speed and airspeed. Finally, conversion-mode dynamic loads were measured on the rotor and these were found to be significantly lower for the new soft-inplane hub than for the previous baseline stiff-inplane hub.
description
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subject:
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EARTH ORBITS
subject
EARTH ORBITS
subject
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subject:
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REUSABLE SPACECRAFT
subject
REUSABLE SPACECRAFT
subject
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subject:
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NUCLEAR ELECTRIC PROPULSION
subject
NUCLEAR ELECTRIC PROPULSION
subject
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subject:
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REUSABLE LAUNCH VEHICLES
subject
REUSABLE LAUNCH VEHICLES
subject
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subject:
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AEROASSIST
subject
AEROASSIST
subject
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subject:
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SOLAR SAILS
subject
SOLAR SAILS
subject
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subject:
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REUSABLE ROCKET ENGINES
subject
REUSABLE ROCKET ENGINES
subject
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subject:
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CRYOGENIC ROCKET PROPELLANTS
subject
CRYOGENIC ROCKET PROPELLANTS
subject
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identifier:
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nasa_techdoc_2003006 6888
identifier
nasa_techdoc_2003006 6888
identifier
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licenseurl:
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uploader:
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gwilliam@archive.org
uploader
gwilliam@archive.org
uploader
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addeddate:
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2011-06-01 07:09:29
addeddate
2011-06-01 07:09:29
addeddate
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publicdate:
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2011-06-01 07:09:29
publicdate
2011-06-01 07:09:29
publicdate
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creator:
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Singleton, Jeffrey D.
creator
Singleton, Jeffrey D.
creator
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creator:
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Nixon, Mark W.
creator
Nixon, Mark W.
creator
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creator:
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Langston, Chester W.
creator
Langston, Chester W.
creator
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creator:
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Piatak, David J.
creator
Piatak, David J.
creator
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creator:
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Kvaternik, Raymond G.
creator
Kvaternik, Raymond G.
creator
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creator:
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Corso, Lawrence M.
creator
Corso, Lawrence M.
creator
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creator:
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Brown, Ros
creator
Brown, Ros
creator
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ImageUID:
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file:/home/lunaadmin /Source_download/201 106/1/nasa_techdoc_2 0030066888/200300668 88.pdf
ImageUID
file:/home/lunaadmin /Source_download/201 106/1/nasa_techdoc_2 0030066888/200300668 88.pdf
ImageUID
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date:
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2003
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rights:
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Public Domain
rights
Public Domain
rights
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ppi:
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300
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year:
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2003
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language:
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eng
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document-source:
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CASI
document_source
CASI
document-source
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documentid:
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20030066888
documentid
20030066888
documentid
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nasa-center:
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Langley Research Center
nasa_center
Langley Research Center
nasa-center
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online-source:
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http://wayback.archi ve-it.org/1792/20100 215231859/http://hdl .handle.net/2060/200 30066888
online_source
http://wayback.archi ve-it.org/1792/20100 215231859/http://hdl .handle.net/2060/200 30066888
online-source
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original-nasa-rights:
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Unclassified; Copyright; Unlimited; Publicly available;
original_nasa_rights
Unclassified; Copyright; Unlimited; Publicly available;
original-nasa-rights
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updated-added-to-ntrs:
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2009-07-29
updated_added_to_ntr s
2009-07-29
updated-added-to-ntr s
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contributor:
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NASA
contributor
NASA
contributor
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identifier-access:
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identifier_access
identifier-access
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identifier-ark:
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ark:/13960/t4xh0gs9w
identifier_ark
ark:/13960/t4xh0gs9w
identifier-ark
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ocr:
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ABBYY FineReader 8.0
ocr
ABBYY FineReader 8.0
ocr
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repub_state:
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4
repub_state
4
repub_state
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