Accession Number : ADA182247

Title :   Use of Blade Sweep to Reduce 4/Rev Hub Loads,

Corporate Author : BOEING VERTOL CO PHILADELPHIA PA

Personal Author(s) : Young,Darrell K ; Tarzanin,Frank J ; Kunz,Donald L

PDF Url : ADA182247

Report Date : May 1987

Pagination or Media Count : 11

Abstract : The effect of blade planform sweep on the 4/rev hub loads for a four-bladed, fully-articulated rotor was analytically investigated. Substantial vibratory hub load reductions could be achieved by using aft tip sweep. However, the mathematical model and the blade definition were too complex to understand the source of the reduction. To aid in understanding the physical mechanism, a model of a simplified blade was defined that still showed substantial hub load reductions. Using this simplified model, an extensive blade parameter sensitivity study was performed. It was determined that those properties which are related to the dynamic torsional response of the blade were important in determining the effectiveness of both aft and forward tip sweep in reducing the 4/rev vertical hub load. An extensive investigation into the source of the hub load reduction was performed, and a number of hypotheses were developed.

Descriptors :   *HELICOPTER ROTORS, *ROTOR BLADES, BLADES, SENSITIVITY, HUBS, REDUCTION, MATHEMATICAL MODELS, MODELS, SIMPLIFICATION, VERTICAL ORIENTATION, DYNAMIC RESPONSE, HYPOTHESES, SOURCES, VIBRATION, ROTARY WINGS, LOADS(FORCES)

Subject Categories : Helicopters

Distribution Statement : APPROVED FOR PUBLIC RELEASE