Effect of three-dimensionality on the flutter threshold of a cantilever plate

Abstract

This paper investigates the effect of three-dimensional flow on the result of a testing rig simulating a two-dimensional theoretical model. The model is a cantilever plate which experiences flutter when the flow velocity exceeds a certain threshold. The plate spans the entire wind-tunnel width but clearance inevitably exists between the plate edges and the wind-tunnel side-walls. Such clearance causes three-dimensional flow around the plate. In this work, we quantify the 3D effect by varying the clearance. A specially-designed partition is used to divide the whole working section into an adjustable one by simultaneously adjusting the upper and lower partitioned wall vertically. The side clearance varies from 0.1 to 5.0 mm with an undisturbed clamp-plate system. The result demonstrates that the critical velocity decreases significantly with the decrease of the clearance in this interesting range of the clearance, a phenomenon which has not been investigated systematically in previous literature. We argue that this effect is an important factor for the understanding of the gap that still exists between published experimental data and 2D-based theories.