Author: G. Alvin Pierce
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 148
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
Author: G. Alvin Pierce
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 148
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.
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 148
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
Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 600
Book Description
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 600
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1278
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1278
Book Description
A Historical Overview of Aeroelasticity Branch and Transonic Dynamics Tunnel Contributions to Rotorcraft Technology and Development
Author:
Publisher: DIANE Publishing
ISBN: 1428995803
Category :
Languages : en
Pages : 115
Book Description
Publisher: DIANE Publishing
ISBN: 1428995803
Category :
Languages : en
Pages : 115
Book Description
Aeronautical Engineering: A Continuing Bibliography, 1982 Cumulative Index
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 768
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 768
Book Description
Monthly Catalog of United States Government Publications
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 596
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 596
Book Description
Monthly Catalogue, United States Public Documents
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1064
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1064
Book Description
The Shock and Vibration Digest
Author:
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 598
Book Description
Publisher:
ISBN:
Category : Shock (Mechanics)
Languages : en
Pages : 598
Book Description
Aeronautical Engineering
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 776
Book Description
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).
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 776
Book Description
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
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 190
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 190
Book Description