Effects of steady angle of attack on nonlinear gust response of a delta wing model

The effects of a steady angle of attack on the nonlinear aeroelastic response of a delta wing model to a periodic gust have been studied. For the theoretical analysis, a three-dimensional time-domain vortex lattice aerodynamic model and a reduced order aerodynamic technique were used and the structure was modelled using von Karman plate theory that allows for geometric strain-displacement nonlinearities in the delta wing structure. Also, an experimental investigation has been carried out in the Duke wind tunnel using a rotating slotted cylinder gust generator and an Ometron VPI 4000 Scanning Laser Vibrometer measurement system to measure deflections (velocities) of a delta wing test model. The fair to good quantitative agreement between theory and experiment verifies that the present analytical approach has reasonable accuracy and good computational efficiency for nonlinear gust response analysis in the time-domain. The results also contribute to a better physical understanding of the nonlinear aeroelastic response of a delta wing model to gust loads when the steady angle of attack is varied. (C) 2002 Elsevier Science Ltd. All rights reserved.