Linear and Nonlinear Flutter of Supersonic Panels of Various Shapes

Abstract

A fluid-structure model based on nonlinear Mindlin-Reissner plate theory and linearized piston theory is used to study the aeroelastic flutter of panels of arbitrary planforms at supersonic Mach numbers. A finite-element procedure is used to reduce the continuous system to a fully coupled finite-dimension flow-structure system, which is solved in the time domain using the Newmark method. Panels with hinged or clamped boundary conditions and surrounded by a rigid baffle are considered. Critical velocity and frequency at onset of flutter are determined for triangular, square, circular, semi-circular, elliptic, and hexagonal forms. Limit cycle oscillations (LCOs) amplitudes are computed for a range of aerodynamic loading for all panels. Based on the finite-element data, scaling laws in the form of simple algebraic formulas are proposed that enable prediction of modal coalescence flutter velocity, frequency, and LCO amplitudes in terms of geometric and materials properties of panels. Such scaling laws are helpful in the preliminary design and optimization of supersonic panels or developing reduced-order models of supersonic panel flutter.