Nonlinear thermal flutter of heated curved panels in supersonic air fow

A nonlinear aeroelastic model for a two-dimensionalheated curved panel in supersonic air flow is established by using Galerkinmethod. The von Karman large deflection theory and the modified pistontheory appended with static aerodynamic loading are used in the formulation.The static deflection of a cylindrical curved panel is studied by numericalsimulation using Newton iterative approach. Then the stability boundarycurves under different temperature elevations are obtained by using Lyapunovindirect method. The motion equations of curved panel are solved byRunge-Kutta method, time history and phase plots of curved panel flutterresponses are depicted and corresponding bifurcation diagrams are obtainedfor better understanding of the subcritical and supercritical flutterresponses of curved panels with different initial height-rises underincreasing dynamic pressure and static thermo-aerodynamic loading (STAL).The results demonstrate that the flutter boundary drops significantly withincreasing temperature elevation for small curvature panel, whereas, theflutter boundary almost keeps the same value for large curvature panel. Theflutter dynamic behaviors of curved panels differ from those of flat panelssignificantly. Curved panels may enter chaos from static stable point whenconsidering temperature elevation effects, and static stable point and LCOmotion also exist in the chaotic motion area. For larger curvatures, chaoticmotions will not occur, however the supercritical flutter motions exhibit alimit strip oscillation in which the vibration amplitudes restrained in alimited range.