Dynamics of a Free-Clamped Cylinder in Confined Axial Flow

The dynamics of a flexible cantilevered cylinder in confined axial flow is studied theoretically and experimentally, in the case where the flow is directed from the free end towards the clamped end. First, the dynamics is described, as observed in specially conducted experiments with air flow; the system developed small-amplitude first-mode vibrations at low flow velocities, which could be flutter, and at higher flows the oscillatory behaviour was succeeded by a static divergence. A simple, linear theoretical model is also developed, and the theoretically predicted behaviour is compared to the experimental one. The model captures the essentials of the observed behaviour, but requires improvement before quantitative prediction can be considered to be adequate.