Accession Number : AD0922797

Title :   Small Disturbance Transonic Flows about Oscillating Airfoils.

Descriptive Note : Technical rept. Jul 73-Jan 74,

Corporate Author : SCIENCE APPLICATIONS INC EL SEGUNDO CA

Personal Author(s) : Traci, R. M. ; Albano, E. D. ; Farr, J. L., Jr. ; Cheng, H. K.

Report Date : JUN 1974

Pagination or Media Count : 126

Abstract : A theory and numerical solution method are presented for the problem of two-dimensional unsteady transonic flow about thin airfoils undergoing harmonic oscillation. The theory is based on a treatment of the unsteady flow as a small perturbation on the non-linear steady flow. The governing equations for the steady and unsteady perturbation potentials are of mixed elliptic/hyperbolic type and are solved by the mixed differencing line relaxation technique of Murman and Cole. Detailed steady and unsteady calculations are performed and compared when possible to available experimental data. The solution procedure is found to be highly efficient and promises further improvements in efficiency through the use of extrapolation schemes. Also the method can be generalized in a straightforward manner to perform calculations with supersonic freestreams and three-dimensional finite wing calculations. (Author)

Descriptors :   (*TRANSONIC FLOW, AIRFOILS), (*AIRFOILS, OSCILLATION), AERODYNAMIC FORCES, FLUTTER, AERODYNAMIC STABILITY, RELAXATION TIME, NUMERICAL METHODS AND PROCEDURES, TWO DIMENSIONAL FLOW, SUPERSONIC FLOW, FREE STREAM, PERTURBATION THEORY, BOUNDARY VALUE PROBLEMS, TURBULENCE, THREE DIMENSIONAL FLOW, MATHEMATICAL PREDICTION, AERODYNAMIC DRAG, ACCURACY.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE