V/STOL Dynamics and Aeroelastic Rotor - Airframe Technology. Volume 2. Description and Correlation of New Methodologies

Abstract

The blade loads analysis calculates rotor blade flapwise, chordwise, and torsional deflections and loads, together with rotor performance, control system forces, and vibratory hub loads. Articulated and hingeless rotors with 2 to 9 blades and large twist may be analyzed. The analysis considers coupled flapwise-chordwise-torsion deflections of the rotor blades. Boundary conditions for either articulated or hingeless rotors are applied and the solution is obtained by expanding the variables in a 10-harmonic Fourier series. Airload calculations include the effects of airfoil section geometry, compressibility, stall, 3-dimensional flow, unsteady aerodynamics, and nonuniform inflow. In the area of rotor loads, correlation of prop/rotor and helicopter rotor loads test data has been made with the fully coupled rotor loads and steady in-plane hub moments for prop/rotors and for alternating blade loads, pitch link loads, and airloads for helicopters. An unexpected discovery of this study was the sensitivity of the rotor derivatives to blade lead-lag motion when the frequency of this mode is near 1 per rev. This result was subsequently confirmed by test. The impact of the new prediction capabilities and possible refinement or development of design criteria through use of the analysis are discussed. The methods contained in this report are intended to be used by designers to calculate with improved accuracy, the dynamic and aeroelastic response characteristics of rotor powered V/STOL aircraft. The essential new feature of these methods is that the coupled flap-pitch-lag blade deflections are taken into account. These calculations are essential if a high level of confidence is to be had in the results.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1972
Accession Number
AD0904089

Entities

People

  • A. K. Amos
  • F. J. Tarzanin
  • H. R. Alexander
  • R. B. Taylor

Organizations

  • Boeing Rotorcraft Systems

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aerodynamic Configurations
  • Aircraft Equipment
  • Aircrafts
  • Airframes
  • Computational Science
  • Dynamic Response
  • Flight Speeds
  • Helicopter Rotors
  • Landing Gear
  • Mach Number
  • Plastic Explosives
  • Spars
  • Test And Evaluation
  • Three Dimensional
  • Tilt Rotor Aircraft
  • Tilt Wings
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Aerospace Engineering
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)