A 2.1-m diam., 1/6-scale model helicopter main rotor was tested in hover in the test section of the NASA Ames 40- by 80- Foot Wind Tunnel. Subsequently, it was tested in forward flight in the Ames 7- by 10-Foot Wind Tunnel. The primary objective of the tests was to obtain performance and noise data on a small-scale rotor at various thrust coefficients, tip Mach numbers, and, in the later case, various advance ratios, for comparisons with similar existing data on full-scale helicopter rotors. This comparison yielded a preliminary evaluation of the scaling of helicopter rotor performance and acoustic radiation in hover and in forward flight. Correlation between model-scale and full-scale performance and acoustics was quite good in hover. In forward flight, however, there were significant differences in both performance and acoustic characteristics. A secondary objective was to contribute to a data base that will permit the estimation of facility effects on acoustic testing.
Hover and Forward Flight Acoustics and Performance of a Small-Scale Helicopter Rotor System
1985
29 pages
Report
No indication
English
Aircraft , Aircraft noise , Radiated noise , Helicopter rotors , Rotor blades(Rotary wings) , Level flight , Acoustic data , Acoustic properties , Acoustics , Test methods , Data bases , Wind tunnels , Hovering , Data acquisition , Acoustic waves , Facilities , Flight , Helicopters , Performance(Engineering) , Mach number , Ratios , Test equipment , Coefficients , Thrust , Forward flight
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