Suppression of Transmitted Harmonic Vertical and Inplane Rotor Loads by Blade Pitch Control

Abstract

A method was developed to study the possibility of using higher harmonic pitch-angle inputs to eliminate the transmission of oscillatory vertical and inplane forces from a helicopter rotor to its driving shaft. The aerodynamic loads are computed by using a realistic model which represents the rotor blades by bound vorticity distributions and the wake by a mesh of segmented vortex filaments. Computed results are presented for a two-bladed teetering rotor which was approximately the same as that of the UH-1A configuration except for the assumed differences in pitch control. The required pitch-angle inputs were determined for eliminating various combinations of harmonic root shears for three flight conditions.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1969
Accession Number
AD0860352

Entities

People

  • John C. Balcerak
  • John C. Erickson Jr.

Organizations

  • Calspan

Tags

DTIC Thesaurus Topics

  • Aerodynamic Forces
  • Aerodynamic Loading
  • Aeronautical Laboratories
  • Army Aviation
  • Centrifugal Force
  • Computer Programs
  • Control Systems
  • Dynamic Response
  • Equations
  • Equations Of Motion
  • Frequency
  • Numerical Analysis
  • Periodic Variations
  • Resonant Frequency
  • Schematic Diagrams
  • Trailing Vortices
  • Vibration

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Structural Dynamics.