Effect of Viscous Flow on the Flutter Threshold of a Cantilever Plate

The flutter of a flexible plate cantilevered vertically at its leading edge has been investigated experimentally in a wind tunnel. As the wind speed exceeds a critical speed (flutter threshold), the cantilever plate would lose its stability and start to flutter. The motivation of this paper is to study the effects of different configurations of the flexible plate on the flutter threshold. The configurations include changing the thickness of airfoil-shape clamp at the plate leading edge to vary the boundary layer thickness of the plate, and inhibiting the plate wake extension by installing a downstream rigid splitter-plate. Test results show that the flutter threshold increases, but not monotonically, with the increase of boundary layer thickness, while decreasing with the downstream extension of the plate wake, indicating that both the boundary layer and the wake suppression can benefit stabilizing the fluid-structure vibration system.