AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF ROTOR TIP SHAPE ON HELICOPTER BLADE-SLAP NOISE
The effect of tip-shape modification on blade-vortex interaction-induced helicopter blade-slap noise was investigated. The general rotor model system (GRMS) with a 3.148 m (10.33 ft) diameter, four-bladed fully articulated rotor was installed in the Langley V/STOL wind tunnel. The tunnel was operated in the open-throat configuration with treatment to improve the semi-anechoic characteristics of the test chamber. Based on previous investigation, four promising tips (ogee, sub-wing, 60 deg swept-tapered, and end-plate) were used along with a standard square tip as a baseline configuration. Aerodynamic and acoustical data concerning the relative applicability of the various tip configurations for blade-slap noise reduction are presented without analysis or discussion.
- Prepared in Cooperation with Army Research and Technology Laboratories, Hampton.
Langley Research CenterNational Aeronautics and Space Administration
Hampton, VA USA 23665
- Hoad, D R
- Publication Date: 1979-5
- Pagination: 464 p.
- TRT Terms: Acoustic measuring instruments; Acoustics; Aerodynamics; Aircraft noise; Airfoils; Helicopters; Noise control; Propeller blades; Rotary wing aircraft; Rotor blades; Rotors; Wind tunnels
- Uncontrolled Terms: Noise reduction
- Old TRIS Terms: Acoustic measurement; Aerodynamic characteristics; Airfoil profiles; Blade tips; Blade-slade noise; Rotary wings
- Subject Areas: Aviation; Vehicles and Equipment;
- Accession Number: 00198897
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: NASA-TM-80066
- Files: TRIS
- Created Date: Oct 17 1980 12:00AM