Accession Number : ADP006226

Title :   Investigation of a Semi-Empirical Method to Predict Limit Cycle Oscillations of Modern Fighter Aircraft,

Corporate Author : NATIONAL AEROSPACE LAB AMSTERDAM (NETHERLANDS)

Personal Author(s) : Meijer, J. J. ; Zwaan, R. J.

Report Date : SEP 1990

Pagination or Media Count : 8

Abstract : Requirements of modern fighters to operate with high maneuverability in the transonic speed regime may, under certain conditions, lead to limit cycle oscillations (LCO), produced by a structural/aerodynamic interaction. Conditions of transonic LCO are moderate angle of attack and Mach numbers ranging from 0.9 to 1.1. Analysis of steady wind tunnel data, obtained for a fighter-type in a typical configuration, indicated that shock-induced separation plays a dominant role. A semi-empirical prediction method is presented which makes use of these steady data, and some results are shown. Possibilities are discussed to extend the method to the use of unsteady wind tunnel data.

Descriptors :   *OSCILLATION, TRANSONIC FLIGHT, FLIGHT MANEUVERS, JET FIGHTERS, ANGLE OF ATTACK, WIND TUNNEL TESTS, EXPERIMENTAL DATA, MATHEMATICAL PREDICTION, NETHERLANDS.

Subject Categories : Aerodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE