Unified panel flutter theory with viscous damping effects

The idea of a unified panel flutter theory, investigated previously by the author, is amplified to make the inclusion of damping effects possible. The paper attempts to study the combined effects of the aerodynamic and structural types of damping on the flutter boundaries for simply supported panels in high supersonic Mach number flows. Classical plate theory and two-dimensional first-order aerodynamics are used. A closed-form rather than modal approach is used in the solution of the partial differential equation in the analysis to avoid convergence problems. The standing and traveling wave theories of panel flutter are compared. The dual nature of damping (stabilizing and destabilizing) is exposed. While the trends are similar to those already established for isotropic panels, the variables compared are generically defined to account for both the isotropic as well as the orthotropic properties of the panels.