Accession Number : AD0284877

Title :   STUDY OF HELICOPTER ROTOR-ROTOR INTERFERENCE EFFECTS ON HUB VIBRATION

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE AEROELASTIC AND STRUCTURES RESEARCH LAB

Personal Author(s) : DUVUVUER,J.F.

Report Date : JUN 1962

Pagination or Media Count : 1

Abstract : A study of the effect of spacing between tandem three-bladed helicopter rotors on the vertical and in-plane shears transmitted at the rear rotor hub was made in a wind tunnel by exciting the rear rotor in resonance with the third harmonic airload. Theoretical third harmonic vertical shears based on Mangler's inflow distribution for a single rotor are compared with the experimental results measured on a single rotor and at the rear rotor of four tandem configurations. First harmonic vertical and inplane shears and sixth harmonic vertical shears are also presented. Pressure measurements made at ten points of one blade were used for correlation with the measured vertical shears, and one case of harmonic airload distribution is presented. Harmonic analyses of the test data are included. (Author)

Descriptors :   *HELICOPTER ROTORS, *ROTOR BLADES (ROTARY WINGS), AERODYNAMIC CHARACTERISTICS, DATA, HARMONIC ANALYSIS, LOAD DISTRIBUTION, MATHEMATICAL ANALYSIS, PRESSURE, RESONANCE, SHEAR STRESSES, THEORY, VIBRATION

Distribution Statement : APPROVED FOR PUBLIC RELEASE