Methods of improving helicopter performance and vibration level by proper shaping of helicopter blade tips are considered. The principle involved consists of reducing the extent of the supersonic zone above the advancing tip and of the turbulent interaction. For stationary and advancing flight, the influence of the rotor and the problems posed by blade tips are reviewed. The theoretical methods of dealing with the two types of flight are briefly stated, and the experimental apparatus is described, including model triple and quadruple rotors. Different blade tip shapes are shown and briefly discussed. The theoretical results include an advancing speed of 309 km/H and a blade tip rotational speed of 215 m/s. The experimental values are advancing speed of 302 km/h and blade tip Mach number 0.86 for both typs of rotors.
Helicopter Blade Tips
1983
28 pages
Report
No indication
English
Aircraft , Aerodynamics , Blade tips , Helicopter design , Helicopter performance , Supersonic flutter , Vortex alleviation , Wing tip vortices , Aerodynamic forces , Horizontal flight , Hovering stability , Rotary wings , Rotor body interactions , Supercritical flow , Tip speed , Foreign technology , Translations
NTRS | 1983
|Aeroelastic Analysis of Helicopter Rotor Blade with Advanced Tips and Trailing Edge Flaps
British Library Conference Proceedings | 1996
|