A 2.1-m-diam, one-sixth-scale model helicopter main rotor was tested in hover at the NASA Ames Outdoor Aerodynamic Research Facility. It had previously been tested in hover in the NASA Ames 40- by 80-Foot Wind Tunnel test section. The primary objective of the tests was to obtain acoustic and performance data on a medium-scale rotor at various thrust coefficients and tip Mach numbers to compare to similar existing data on a full-scale helicopter main rotor. Information is presented on the effects of thrust- and tip-speed variation, the effects of boundary-layer trip strips, and the effects of wind conditions. In addition, a preliminary evaluation of the scaling of helicopter main-rotor noise in hover is presented. A secondary objective was to contribute to a data base that will permit the estimation of facility effects on acoustic testing.
Scaling of helicopter main rotor noise in hover
01.01.1986
Aufsatz (Konferenz)
Keine Angabe
Englisch
Scaling of helicopter main rotor noise in hover
AIAA | 1986
|A study of helicopter main rotor noise in hover
AIAA | 1986
|A study of helicopter main rotor noise in hover
NTRS | 1986
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AIAA | 1999
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