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Whirl Flutter Stability and Its Influence on the Design of the Distributed Electric Propeller Aircraft X- 57This paper studies the whirl flutter stability of the NASA experimental electric propulsion aircraft designated the X-57 Maxwell. whirl flutter stability is studied at two flight conditions: sea level at 2700 RPM to represent take-off and landing and 8000 feet at 2250 RPM to represent cruise. Two multibody dynamics analyses are used: CAMRAD II and Dymore. The CAMRAD II model is a semi-span X-57 model with a modal representation for the wing/pylon system. The Dymore model is a semi-span wing with a propeller composed of beam elements for the wing/pylon system that airloads can be applied to. The two multibody dynamics analyses were verified by comparing structural properties between each other and the NASTRAN analysis. For whirl flutter, three design revisions of the wing and pylon mount system are studied. The predicted frequencies and damping ratio of the wing modes show good agreements between the two analyses. Dymore tended to predict a slightly lower damping ratio as velocity increased for all three dynamic modes presented. Whirl flutter for the semi-span model was not present up to 500 knots for the latest design, well above the operating range of the X-57.
Document ID
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Hoover, Christian B.
(Alabama Univ. Tuscaloosa, AL, United States)
Shen, Jinwei
(Alabama Univ. Tuscaloosa, AL, United States)
Kreshock, Andrew R.
(Army Research Lab. Hampton, VA, United States)
Stanford, Bret K.
(NASA Langley Research Center Hampton, VA, United States)
Piatak, David J.
(NASA Langley Research Center Hampton, VA, United States)
Heeg, Jennifer
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
July 3, 2017
Publication Date
June 5, 2017
Subject Category
Report/Patent Number
Meeting Information
Meeting: AIAA Aviation 2017 Conference
Location: Denver, CO
Country: United States
Start Date: June 5, 2017
End Date: June 9, 2017
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 432938.
Distribution Limits
Public Use Permitted.
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