Accession Number : ADA182870

Title :   Helicopter Blade Dynamic Loads Measured During Performance Testing of Two Scaled Rotors.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER

Personal Author(s) : Berry,John D

PDF Url : ADA182870

Report Date : Jul 1987

Pagination or Media Count : 50

Abstract : A test to determine the performance differences between the 27-percent-scale models of two rotors for the U.S. Army AH-64 helicopter was conducted in the Langley 14- by 22-Foot Subsonic Tunnel. One rotor, referred to as the baseline rotor, simulated the geometry and dynamic characteristics of the production baseline rotor, and the other rotor, referred to as the advanced rotor, was designed to have improved hover performance. During the performance test, the dynamic pitch-link forces and blade bending and torsion moments were also measured. Dynamic data from the forward flight investigation have been reduced and are presented herein. The advanced blade set was designed to have dynamic characteristics similar to those of the baseline rotor so that test conditions would not be limited by potential rotor instability and blade resonances and so that the measured performance increments could be considered to be due purely to aerodynamic causes. Data show consistent trends with advance ratio for both blade sets with generally higher oscillatory loads occurring for the advanced blade set when compared with the baseline blade set.

Descriptors :   *ROTOR BLADES(ROTARY WINGS), BASE LINES, BLADES, BENDING, LEVEL FLIGHT, HOVERING, ROTORS, RESONANCE, CONSISTENCY, PATTERNS, DYNAMICS, DYNAMIC LOADS, HELICOPTERS, ATTACK HELICOPTERS, AERODYNAMIC CHARACTERISTICS, SCALE MODELS, PITCH(MOTION), AERODYNAMIC LOADING, OSCILLATION, SUBSONIC WIND TUNNELS, PERFORMANCE(ENGINEERING), PERFORMANCE TESTS, STABILITY, RATIOS, PRODUCTION, MOMENTS, TORSION

Subject Categories : Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE