Nonlinear Flutter Of Aeroelastic Panel In Subsonic Flow

With the increasing velocity of high-speed train, the instability of the panel structure in high-speed train under aerodynamic pressure is more and more concerned by people. The velocity of high-speed train is basically in the low-subsonic range, and the Mach number approximately equals0.3. In order to research the stability of the panel structure of high-speed train, the dynamical panel models in subsonic flow are set up, and the differential quadrature (DQ) method is used to discretize the governing motion equations into a series of ordinary differential equations. The eigenvalue method is used to analyze the instability characteristics of the panels. The main contributions of this dissertation are as follows:1. Based on the potential flow theory, the approximate analytic expression of aerodynamic forces acting on the panel is obtained, which is simplified and combined with the governing motion equation of the two-dimensional panel. The discrete forms of the continuation equation are obtained by the Galerkin method and DQ method. The eigenvalue method is applied to study the stability of the panel, and the result shows that the two-dimensional panel lose its stability by flutter.2. Nonlinear flutter of a two-dimensional panel in subsonic flow is studied. The DQ Method is used to discretize the equation of the panel motion, and the Runge-Kutta method is adopted to conduct numerical simulation. The nonlinear responses of the panel were presented in bifurcation diagrams and phase plots. Results show that the panel undergoes complex nonlinear dynamics in subsonic flow.3. The nonlinear flutter of a two-dimensional viscoelastic panel with geometric nonlinearity is studied. The Galerkin method and DQ method are used to derive the discrete form of differential equation of the panel motion, and then the Runge-Kutta method is adopted to perform numerical simulation. The numerical results are presented in bifurcation diagrams and phase plots, which show that the system is full of complex nonlinear dynamics as the dynamic pressure and viscoelastic coefficient varying.