Tability analysis of heated panels in supersonic air flow

An investigation on stability of heated panels in supersonic air flow is carried out in this paper. A nonlinear aeroelastic model for a two-dimensional heated panel is established using Galerkin method. The quasi-steady piston theory is employed to calculate the aerodynamic load on the panel and the even temperature field is considered. At first, the static and dynamic stabilities for flat panels are studied by using Lyapunov's indirect method and the stability boundary curve is obtained. Then the static deformation of a post-buckled panel is calculated by Newton iterative approach, and the local stability of the post-buckling equilibrium is analyzed. The results show that a two-mode model is suitable for panel static stability analysis and static deformation calculation; but more than four modes are required for dynamic stability analysis. The effects of temperature elevation and non-dimensional parameters related to panel length/thickness ratio, material density and Mach number on the stability of heated panels are also investigated. It is found that panel flutter (secondary instability) may occur at relatively low aerodynamic pressure when there are several stable equilibrium points for the aeroelastic system of heated panels.