On the aeroelastic instability of two-dimensional panels in uniform incompressible flow

A theoretical and experimental study is presented of the aeroelastic instability of a panel with various boundary conditions on its leading and trailing edges, exposed to air flow over its upper surface or on both sides. The flow is incompressible and two-dimensional (no span-wise deformation of the panel). The case of a panel clamped at its leading edge and free at its trailing edge is investigated both theoretically and experimentally. Agreement between theory and experiment is fair. The aerodynamic theory of steady non-circulatory flow is applied for panels fixed at both ends, and the quasi-steady and full unsteady aerodynamic lifting theories to a cantilevered panel (free at the trailing edge). The analogy with incompressible flow through a long slender tube is pointed out. Theory shows that a panel with both ends fixed loses its stability by divergence, while the instability of a cantilevered panel is of a flutter type. The latter is also confirmed experimentally.