Accession Number : ADP005035

Title :   Theoretical Prediction of Wing Rocking,

Corporate Author : KANSAS UNIV LAWRENCE

Personal Author(s) : Lan,C. E.

Report Date : NOV 1985

Pagination or Media Count : 13

Abstract : Wing rock is primarily a rolling oscillation about the longitudinal body axis at high angles of attack. It involves nonlinear interaction between flight dynamics and aerodynamics. A nonlinear aerodynamic model was proposed earlier to predict the wing rock frequency and amplitude of low aspect-ratio configurations with good accuracy. In this paper, the theory is applied to a twin-jet fighter airplane of moderate aspect ratio and to a low-speed configuration of high aspect ratio. For the purpose of predicting necessary aerodynamic derivatives, a lifting surface method coupled with nonlinear airfoil section data is developed. The results show that wing rock can be predicted with the present wing-rock and aerodynamic theories. It is also found that for configurations of high aspect ratio, the one degree-of-freedom dynamic model in the present wing-rock theory should be used; for other configurations, the three degree-of-freedom model is more appropriate.

Descriptors :   *WINGS, OSCILLATION, ROLL, ANGLE OF ATTACK, HIGH ANGLES, DERIVATIVES(MATHEMATICS), AERODYNAMICS, INTERACTIONS, NONLINEAR SYSTEMS, FLIGHT, MATHEMATICAL MODELS, NONLINEAR ANALYSIS, ASPECT RATIO, JET FIGHTERS, AIRFOILS, LIFTING SURFACES, FREQUENCY, AMPLITUDE, MATHEMATICAL PREDICTION

Distribution Statement : APPROVED FOR PUBLIC RELEASE