Dynamic Stall Measurements and Computations for a VR-12 Airfoil with a Variable Droop Leading Edge
Abstract
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2003
- Accession Number
- ADA480698
Entities
People
- K. W. Mcalister
- M. S. Chandrasekhara
- P. B. Martin
- W. Geissler
Organizations
- National Aeronautics and Space Administration