Analysis of nonlinear panel flutter

Nonlinear panel flutter caused by the interaction between nonlinear fluid and geometrically nonlinear structure is studied by an improved computational fluid dynamics and computatienal structural dynamics (CFD/CSD) coupled program. A flux splitting scheme combined with implicit time marching technology and geometric conservation law is utilized to solve unsteady aerodynamic pressure; the finite element corotational theory is applied to modeling the geometric nonlinear two-dimensional and three-dimensional panels, and an approximate energy conservation algorithm is developed to obtain nonlinear structure response. The two solvers are connected by a second-order loosely coupled method and applied to the solution of panel flutter problems for supersonic, transonic and subsonic Mach numbers. A representative limited cycle oscillation appears when geometric nonlinearity and aerodynamic nonlinearity are considered. The flutter boundary and amplitude of limit cycle oscillation are discussed.