Measurement of Aerodynamic Forces for Various Mean Angles of Attach on an Airfoil Oscillating in Pitch and on Two Finite-Span Wings Oscillating in Bending with Emphasis on Damping in the Stall
Abstract
The oscillating air forces on a two-dimensional wing oscillating in pitch about the midchord have been measured at various mean angles of attack and at Mach numbers of 0.35 and 0.7. The magnitudes of normal-force and pitching-moment coefficients were much higher at high angles of attack than at low angles of attack for some conditions. Large regions of negative damping in pitch were found, and it was shown that the effect of increasing the Mach number from 0.35 to 0.7 was to decrease the initial angle of attack at which negative damping occurred. Measurements of the aerodynamic damping of a 10-percent-thick and of a 5-percent-thick finite-span wing oscillating in the first bending mode indicate no regions of negative damping for this type of motion over the range of variables covered. The damping measured at high angles of attack was generally larger than that at low angles of attack.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1956
- Accession Number
- ADA377323
Entities
People
- A. G. Rainey
Organizations
- National Aeronautics and Space Administration