A PERTURBED-PENDULUM MODEL FOR FLAT-PLATE AUTOROTATION

Global bifurcations of a perturbed planar-pendulum model for nonconservative systems capable of oscillation and rotation are analysed. The motions correspond to stable and unstable limit cycles following a saddle-node bifurcation. The parameter space may be divided into six regions of topologically distinct behavior. The model is applied to the phenomenon of flat-plate autorotation. Using experimental data, the model parameters are empirically fitted physical quantities. Predictions of angular velocity and the critical values of flow velocity and inertia for the onset of autorotation are in good agreement with the experimental observations of previous investigators. © 1994 Academic Press.