Effects of a Free-to-Roll Fuselage on Wing Flutter: Theory and Experiment

摘要

A theoretical study of a wing-fuselage combination with a rigid-body roll degree of freedom for the fuselage and elastic modes for the wing is presented along with a companion wind-tunnel test The full-span wing dynamics are modeled using a linear-plate wing structure theory. A component modal analysis is used to derive the full structural equations of motion for the wing-fuselage combination system. A three-dimensional time-domain vortex-lattice aerodynamic model is also used to investigate flutter of the linear aeroelastic system. The experimentally observed flutter mode is antisymmetric, although theory suggests that the symmetric-mode flutter velocity is only modestly higher than that for the antisymmetric modes. Correlation between theory and experiment for flutter velocity and frequency is good. The experimentally observed postflutter response is a limit-cycle oscillation, and this is worthy of further study using an appropriate nonlinear theory.