Additional Results of a Study of Unsteady Airfoil Surface Pressures and Turbulent Boundary Layers
Abstract
Unsteady pressure coefficients measured on an N.A.C.A. 0012 airfoil at geometric angles of attack of 0 and 10 degrees, Reynolds numbers of 700,000 and 1,000,000 and in the reduced frequency range of 0.5 to 6.4 (based upon the half chord) are presented. For simplicity the data are represented in terms of mean and unsteady pressure coefficients, which has both a magnitude and a phase. Primary conclusions are: (1) The difference pressures approach zero at the trailing edge. This corresponds to satisfying one statement of the Kutta condition. (2) Superposition of the unsteady processes in the steady flow seems accurate and valid up to reduced frequencies of 2. (3) For this airfoil with 16 deg trailing edge angle the effects of viscosity seem to be most prominent in the last 10 percent of the airfoil where the phase lags are much larger than those predicted by the linear theory. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1981
- Accession Number
- ADA108978
Entities
People
- Eugene E. Covert
- Peter F. Lorber
Organizations
- Massachusetts Institute of Technology