Accession Number:

AD0269586

Title:

HELICOPTER ROTOR HUB VIBRATORY FORCES SYSTEMATIC VARIATION OF FLEXIBLE ROTOR BLADE PARAMETERS

Descriptive Note:

Corporate Author:

BOEING CO MORTON PA VERTOL DIV

Personal Author(s):

Report Date:

1961-05-01

Pagination or Media Count:

1.0

Abstract:

A study was made of the effect on vibratory hub loads of systematic variations in blade mass, planform, twist distribution, flap and chord bending stiffness, pitch control stiffness, pitch axis - chordwise center of gravity axis aerodynamic center axis locations, lag damper and lag spring rates. The variations are made with respect to the standard blade of a typical single rotor helicopter having a gross weight of 8000 lbs. The results are based on an Associated Matrix flexible blade analysis using classical linearized blade element aerodynamic theory for the first four harmonic airloadings uniform inflow is assumed and the effects of compressibility and stall are neglected. Results indicate that there are some parameter selections which reduce both vertical and horizontal loads, others which reduce one and increase the other, and some which increase both. The results can therefore be used to select optimum parameter trends for given helicopter applications wherein longitudinal and vertical hub loads may be inducing com ensatory response amplitudes. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE