The Effect of Varying Freestream Velocity on Airfoil Dynamic Stall Characteristics
A low speed wing tunnel equipped with an axial gust generator to simulate the aerodynamic environment of a helicopter rotor was used to study the dynamic stall of a pitching blade. The objective of this investigation was to find out to what extent harmonic velocity perturbations in
the freestream affect dynamic stall. The study involved making measurements of the aerodynamic moment on a two‐dimensional, pitching blade model in both constant and pulsating airstreams. Using an operational analog computer to perform on‐line data reduction, plots of moment
versus angle of attack and work done by the moment were obtained. The data taken in the varying freestream were then compared to constant freestream data, and to the results of two analytical methods. These comparisons showed that the velocity perturbations had a significant effect on the
pitching moment which could not be consistently predicted by the analytical methods, but had no drastic effect on the blade stability.
Document Type: Research Article
Affiliations: Georgia Institute of Technology, Atlanta, Georgia
Publication date: 01 April 1978
The Journal of the AHS is the world's only scientific journal dedicated to vertical flight technology. It is a peer-reviewed technical journal published quarterly by The Vertical Flight Society and presents innovative papers covering the state-of-the-art in all disciplines of VTOL design, research and development. (Please note that VFS members receive significant discounts on articles and subscriptions.)
Journal subscribers who are VFS members log in here if you are not already logged in.
Authors can find submission guidelines and related information on the VFS website.
- Access Key
- Free content
- Partial Free content
- New content
- Open access content
- Partial Open access content
- Subscribed content
- Partial Subscribed content
- Free trial content