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Accession Number N20120012536
Title Loads Correlation of a Full-Scale UH-60A Airloads Rotor in a Wind Tunnel.
Publication Date Apr 2012
Media Count 23p
Personal Author E. A. Romander H. Yeo
Abstract Wind tunnel measurements of the rotor trim, blade airloads, and structural loads of a full-scale UH-60A Black Hawk main rotor are compared with calculations obtained using the comprehensive rotorcraft analysis CAMRAD II and a coupled CAMRAD II/OVERFLOW 2 analysis. A speed sweep at constant lift up to an advance ratio of 0.4 and a thrust sweep at constant speed into deep stall are investigated. The coupled analysis shows significant improvement over comprehensive analysis. Normal force phase is better captured and pitching moment magnitudes are better predicted including the magnitude and phase of the two stall events in the fourth quadrant at the deeply stalled condition. Structural loads are, in general, improved with the coupled analysis, but the magnitude of chord bending moment is still significantly underpredicted. As there are three modes around 4 and 5/rev frequencies, the structural responses to the 5/rev airloads due to dynamic stall are magnified and thus care must be taken in the analysis of the deeply stalled condition.
Keywords Aerodynamic loads
Aerodynamic stalling
Pitching moments
Rotary wing aircraft
Wind tunnel tests

Source Agency National Aeronautics and Space Administration
NTIS Subject Category 51A - Aerodynamics
51C - Aircraft
Corporate Author National Aeronautics and Space Administration, Moffett Field, CA. Ames Research Center.
Document Type Conference proceedings
Title Note N/A
NTIS Issue Number 1303
Contract Number N/A

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