23rd Congress of International Council of the Aeronautical Sciences, 8-13 September, 2002, Toronto, Canada
Paper ICAS 2002-4.4.5

INVESTIGATION OF SHOCK-INDUCED LCO OF A WING/STORE CONFIGURATIONUSING THE TRANSONIC SMALL DISTURBANCE METHOD

F. Eastep, N. S. Khot, P. S. Beran, J. V. Zweber, R. D. Snyder
AFRL/VASD, USA

Keywords: limit cycle oscillation, aeroelasticity

Fighter aircraft with external stores are susceptible to limit-cycle oscillation (LCO) in transonic flight. LCO requires an accurate prediction of flow conditions, which will initiate the oscillations and occur at a speed somewhat below the flutter speed. Transonic small disturbance (TSD) aerodynamic theory is used to fully capture the features of LCO and is used to predict the conditions for the initiation of LCO for a wing with a tip store. For the wing/store configuration investigated, limit cycle oscillations are obtained at speeds lower than those predicted for wing/store flutter. Comparisons of LCO amplitudes are given for inviscid and viscous aerodynamics.

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