Aeroelastic Analysis and Experiment for Wing/Store Model with Stiction Nonlinearity

Abstract

An experimental delta wing/store model with stiction nonlinearity has been designed and tested in a low-speed wind tunnel. The wing structure ismodeled theoretically using vonKarman plate theory that accounts for geometric strain-displacement nonlinearities in the plate wing structure. A component modal analysis is used to derive the full structural equations of motion for the wing/store system. A linear three-dimensional time-domain vortex-lattice aerodynamic model including a reduced-order model aerodynamic technique and a slender-body aerodynamic theory for the store are also used to investigate the nonlinear aeroelastic system. The dynamic behavior of the stiction nonlinearity in the store model has been experimentally measured and determined. The effects of the stiction gap angle and the initial store pitch angle on the limit cycle oscillations are discussed. The correlations between the theory and experiment are good for the smaller limit cycle oscillation amplitudes and for flow velocities between the onset of limit cycle oscillations and the linear flutter velocity and slightly higher than the flutter velocity. At yet higher flow velocities, the theoretical and experimental correlations are not as good.