Accession Number : AD0748457

Title :   The Response of a Model Helicopter Rotor Blade to Random Excitation During Forward Flight.

Descriptive Note : Final rept. 18 May 65-17 Aug 72,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TEX

Personal Author(s) : Kana,Daniel D. ; Chu,Wen-Hwa

Report Date : 15 AUG 1972

Pagination or Media Count : 52

Abstract : The response of a model helicopter rotor blade to random excitation while in simulated forward flight is studied analytically and experimentally by means of an electromechanical apparatus. Complex transfer functions are defined which relate steady-state responses in bending, flapping, and torsion modes to a sine input. Responses occur at the input and side-band frequencies. These transfer functions are then used along with excitation power spectra to predict the nonstationary time-averaged power spectrum of the response. Validity of the transfer function analysis is investigated by means of the electromechanical model which includes analog computer simulation of the interaction of blade deflections and aerodynamic load. (Author)

Descriptors :   (*ROTOR BLADES(ROTARY WINGS), FLUTTER), (*HELICOPTERS, LEVEL FLIGHT), EXCITATION, AERODYNAMIC LOADING, EQUATIONS OF MOTION, RESPONSE, BENDING, TRANSFER FUNCTIONS

Subject Categories : Aerodynamics
      Helicopters
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE