Helicopter Vibration Suppression Using Simple Pendulum Absorbers on the Rotor Blade

Helicopter Vibration Suppression Using Simple Pendulum Absorbers on the Rotor Blade PDF Author: G. Alvin Pierce
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 148

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Book Description
The objectives of the present investigation are: (1) Develop a mathematical model to represent the blade-pendulum system. A single nonuniform rotor blade with a hingeless hub restraint undergoing coupled flapwise bending, chordwise bending, and torsional vibrations is considered. Simple pendulum absorbers are individually treated for both flap and lead-lag types of motion. The blade is excited by an azimuthal harmonic variation of spanwise airload distributions associated with the elastic deformations and the cyclic pitch environment of forward flight; (2) Find the dynamic response characteristics of the blade-pendulum system, using the transfer matrix method; (3) Determine the optimum pendulum tuning to suppress the hub reactions. This entails the minimization of these reactions by appropriate variations of the pendulum parameters for a given excitation frequency. The pendulum parameters include the uncoupled pendulum frequency, hinge spanwise location and pendulum mass; and (4) Conduct a parametric study of the optimum tuned configuration. The parameters to be varied include pendulum hinge offset, precone, prepitch and pretwist. The intention of this investigation is to document the effects of these parameters on the optimum configuration previously established and thereby provide useful design criteria for future installations of pendulum absorbers.

Helicopter Vibration Suppression Using Simple Pendulum Absorbers on the Rotor Blade

Helicopter Vibration Suppression Using Simple Pendulum Absorbers on the Rotor Blade PDF Author: G. Alvin Pierce
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 148

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Book Description
The objectives of the present investigation are: (1) Develop a mathematical model to represent the blade-pendulum system. A single nonuniform rotor blade with a hingeless hub restraint undergoing coupled flapwise bending, chordwise bending, and torsional vibrations is considered. Simple pendulum absorbers are individually treated for both flap and lead-lag types of motion. The blade is excited by an azimuthal harmonic variation of spanwise airload distributions associated with the elastic deformations and the cyclic pitch environment of forward flight; (2) Find the dynamic response characteristics of the blade-pendulum system, using the transfer matrix method; (3) Determine the optimum pendulum tuning to suppress the hub reactions. This entails the minimization of these reactions by appropriate variations of the pendulum parameters for a given excitation frequency. The pendulum parameters include the uncoupled pendulum frequency, hinge spanwise location and pendulum mass; and (4) Conduct a parametric study of the optimum tuned configuration. The parameters to be varied include pendulum hinge offset, precone, prepitch and pretwist. The intention of this investigation is to document the effects of these parameters on the optimum configuration previously established and thereby provide useful design criteria for future installations of pendulum absorbers.

The Shock and Vibration Digest

The Shock and Vibration Digest PDF Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 600

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1278

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A Historical Overview of Aeroelasticity Branch and Transonic Dynamics Tunnel Contributions to Rotorcraft Technology and Development

A Historical Overview of Aeroelasticity Branch and Transonic Dynamics Tunnel Contributions to Rotorcraft Technology and Development PDF Author:
Publisher: DIANE Publishing
ISBN: 1428995803
Category :
Languages : en
Pages : 115

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Aeronautical Engineering: A Continuing Bibliography, 1982 Cumulative Index

Aeronautical Engineering: A Continuing Bibliography, 1982 Cumulative Index PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 768

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Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 596

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Monthly Catalogue, United States Public Documents

Monthly Catalogue, United States Public Documents PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1064

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The Shock and Vibration Digest

The Shock and Vibration Digest PDF Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 598

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Aeronautical Engineering

Aeronautical Engineering PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 776

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A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).

Technical Abstract Bulletin

Technical Abstract Bulletin PDF Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 190

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