Nonlinear Aeroelastic Study for Folding Wing Structures

摘要

A folding wing structure consisting of three components: fuselage, inboard wing and outboard wing, is modeled computationally using a geometrically nonlinear structural dynamics theory based upon von Karman strains and at three-dimensional nonlinear potential flow aerodynamic model. The structural dynamic equations of motion are discretized in space using a discrete Ritz basis derived from finite element analysis and component synthesis and the aerodynamic model is discretized using a vortex lattice. Results from the computational model are compared to those from experiments designed and tested in the Duke University wind tunnel for three folding wing configurations. It is found that limit cycle oscillation magnitude and frequency results from theory compare well with those measured in the experiment. Also it appears that structural nonlinearities are stronger than aerodynamic nonlinearities for the cases studied.