Accession Number : ADP006230

Title :   Unsteady Separated Flow Phenomena Causing Self-Excited Structural Oscillations,

Corporate Author : LOCKHEED MISSILES AND SPACE CO INC SUNNYVALE CA

Personal Author(s) : Ericsson, L. E.

Report Date : SEP 1990

Pagination or Media Count : 16

Abstract : Because of steadily increasing performance demands, both aircraft and missiles operate at high angles of attack where separated flow often has a dominant influence on, especially, the unsteady aerodynamics. The penetration of the buffet boundary usually changes the structural response from the buffet-type to the self-excited type. This transfer occurs when the structural response starts interacting with the unsteady flow separation, generating negative aerodynamic damping. Separated flow aerodynamics are usually very nonlinear, and the self-excited response frequently takes the form of a limit-cycle oscillation.

Descriptors :   *FLOW SEPARATION, UNSTEADY FLOW, INTERACTIONS, BUFFETING, STRUCTURAL RESPONSE, EXCITATION, ANGLE OF ATTACK, HIGH ANGLES, DAMPING, OSCILLATION.

Subject Categories : Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE