High density-altitude operations of helicopters with advanced performance and maneuver capabilities have lead to fundamental research on active high-lift system concepts for rotor blades. The requirement for this type of system was to improve the sectional lift-to-drag ratio by alleviating dynamic stall on the retreating blade while simultaneously reducing the transonic drag rise of the advancing blade. Both measured and computational results showed that a Variable Droop Leading Edge (VDLE) airfoil is a viable concept for application to a rotor high-lift system. Results are presented for a series of 2D compressible dynamic stall wind tunnel tests with supporting CFD results for selected test cases. These measurements and computations show a dramatic decrease in the drag and pitching moment associated with severe dynamic stall when the VDLE concept is applied to the Boeing VR-12 airfoil. Test results also show an elimination of the negative pitch damping observed in the baseline moment hysteresis curves.
Dynamic Stall Measurements and Computations for a VR-12 Airfoil with a Variable Droop Leading Edge
AHS International Forum 59 ; 2003 ; Phoenix, AZ, United States
2003-01-01
Preprint
No indication
English
DYNAMIC STALL MEASUREMENTS AND COMPUTATIONS FOR A VR-12 AIRFOIL WITH A VARIABLE DROOP LEADING EDGE
British Library Conference Proceedings | 2003
|Compressible Dynamic Stall Control using a Variable Droop Leading Edge Airfoil
British Library Conference Proceedings | 2003
|