Retreating side helicopter blades often experience stall when flying at high speeds or at high thrust. There are a number of consequences to stall which result in significant increases in blade stresses, vibration levels, pitch link loads and required shaft power. No real confidence exists today for the prediction of these effects on actual helicopter rotors since the models used in existing aeroelastic codes have usually been elaborated from simple 2D wind tunnel tests. A GARTEUR Action Group (Group for Aeronautical Research and Technology in EURope) has been assembled to evaluate the capabilities of the up-to-date dynamic stall models used in Europe for the prediction of rotor behavior in presence of stall, the work of which is reported here. Seven different stall models are described and then fitted to reproduce to experimental 2D hysteresis loops. A series of calculations is then carried out for a flight condition with a high load factor. The unsteady stall models used are finally evaluated against detailed measurements on a model rotor in a wind tunnel. Conclusions are drawn relative to the state-of-the-art of dynamic stall models, blade torsion and of rotor calculations in general.
Stall effects and blade torsion - An evaluation of predictive tools
Strömungsabreißeffekte und Torsionsspannung - eine Bewertung von Vorhersagemodellen
Journal of the American Helicopter Society ; 44 , 4 ; 320-331
1999
12 Seiten, 4 Bilder, 2 Tabellen, 16 Quellen
Article (Journal)
English
Hubschrauber , Rotor (Drehflügel) , Fluggeschwindigkeit (Luft) , Schub (Antrieb) , Abreißen der Strömung , Schwingungsanregung , Torsionsspannung , Vorhersage , elastische Eigenschaft , Computer-Programm , Windkanal , Software-Entwicklung , Simulationsmodell , dynamisches Verhalten , Hystereseschleife , Lastfaktor , instationäre Strömung , Vergleichsmessung
Stall Effects and Blade Torsion - An Evaluation of Predictive Tools
Online Contents | 1999
|Stall effects and blade torsion - an evaluation of predictive tools
Tema Archive | 1997
|Stall Effects and Blade Torsion - An Evaluation of Predictive Tools
British Library Conference Proceedings | 1997
|Emerald Group Publishing | 1942