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dc.contributor.advisorWood, E. Roberts
dc.contributor.advisorCouch, Mark A.
dc.contributor.authorRauchenstein, Werner J.
dc.date.accessioned2012-03-14T17:42:21Z
dc.date.available2012-03-14T17:42:21Z
dc.date.issued2002-09
dc.identifier.urihttp://hdl.handle.net/10945/4580
dc.descriptionApproved for public release; distribution is unlimiteden_US
dc.description.abstractThis thesis presents a fully coupled, quasi-3D analysis of rotor blade flutter that can accommodate forward flight conditions. The rotor blade is modeled as a uniform beam, taking the average characteristics of a real blade between 20% and 90% of its length. Applying Rayleigh's method, the first few bending and torsion normal mode shapes and natural frequencies are determined, and then adjusted for the rotating case. With this data, force and moment equations of motion are developed using Lagrange's equation along with a normal mode analysis. Theodorsen coefficients are calculated over a range of forward velocities (input as reduced frequencies) for a specified number of elements along the blade model. Incorporating these coefficients into the equations of motion, a square matrix is generated from which complex eigenvalues can be derived. These eigenvalues provide the aeroelastic natural frequencies and damping coefficients for each coupled mode. The forward velocity at which one of the modes produces a positive damping coefficient gives the value of reduced frequency for the flutter point. The resulting forward speed and blade tip speed can then be determined.en_US
dc.description.urihttp://archive.org/details/adtheodorsenbase109454580
dc.format.extentxvi, 57 p. : ill. (some col.) ;en_US
dc.publisherMonterey, California. Naval Postgraduate Schoolen_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, may not be copyrighted.en_US
dc.subject.lcshHelicoptersen_US
dc.subject.lcshAerodynamicsen_US
dc.subject.lcshRotors (Helicopters)en_US
dc.subject.lcshFlutter (Aerodynamics)en_US
dc.titleA 3D Theodorsen-based rotor blade flutter model using normal modesen_US
dc.typeThesisen_US
dc.description.serviceLieutenant, United States Navyen_US
etd.thesisdegree.nameM.S. in Aeronautical Engineeringen_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineAeronautical Engineeringen_US
etd.thesisdegree.grantorNaval Postgraduate Schoolen_US
etd.verifiednoen_US


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