AN INVESTIGATION OF THE FORCES ON AN AIRFOIL OSCILLATING IN PITCH ABOUT THE QUARTER CHORD,
Abstract
The lift and moment on an airfoil oscillating in pitch about the quarter chord line in an incompressible non-cavitating flow was determined. Theoretical values were obtained by using Theodorsen's analysis. The contributions of the various terms in the theory were investigated to explain the deviation between theory and test results. At high values of the reduced frequency parameter, defined as the ratio between a characteristic body length and a wave length of the hydrodynamic disturbances, it is shown that existing theories are unreliable. This fact is supported by the results of this investigation. Some of the basic assumptions dnderlying existing theories are examined, such as the satisfacti n of the Kutta-Joukowski trailing edge condition. Some photographs of the vortex formation in the wake of an oscillating airfoil are presented. The model, dynamic balance system, and oscillating system designed and used for this investigation are discussed in detail. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 12, 1964
- Accession Number
- AD0438890
Entities
People
- F. E. Smith
- M. Sevik
Organizations
- Pennsylvania State University