Investigation of Rotor Performance and Loads of a UH-60A Individual Blade Control System
Abstract
Wind tunnel measurements of performance, loads, and vibration of a full-scale UH-60A Black Hawk main rotor with an individual blade control (IBC) system are compared with calculations obtained using the comprehensive helicopter analysis CAMRAD II and a coupled CAMRAD II/OVERFLOW 2 analysis. Measured data show a 5.1% rotor power reduction (8.6% rotor lift to effective-drag ratio increase) using 2/rev IBC actuation with 2.0 deg amplitude at mu = 0.4. At the optimum IBC phase for rotor performance, IBC actuator force (pitch link force) decreased, but both flap and chord bending moments did not change much. CAMRAD II predicts the rotor power variations with IBC phase reasonably well at mu = 0.35. However, the correlation degrades at mu = 0.4. Coupled CAMRAD II/OVERFLOW 2 shows excellent correlation with the measured rotor power variations with IBC phase at both mu = 0.35 and mu = 0.4. Maximum reduction of IBC actuator force is better predicted with CAMRAD II, but general trends are better captured with the coupled analysis. The correlation of vibratory hub loads is generally poor by both methods, although the coupled analysis somewhat captures general trends.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2010
- Accession Number
- ADA532073
Entities
People
- Ethan A. Romander
- Hyeonsoo Yeo
- Thomas R. Norman