An Unsteady Theory For Fluidelastic Instability in an Array of Flexible Tubes in Cross-Flow. Part I: Theory

Abstract An unsteady theoretical model for fluidelastic instability in an array of tubes in cross-flow is presented. The model is based on concepts developed by Lever and Weaver, but is extended to overcome some of the problems encountered with that earlier work. A perturbation decay function is introduced to account for decay of disturbances away from a moving tube, and the theory includes the effects of neighbouring tube motion. The theory is applicable to all standard array geometries and is shown to reduce to a model of a single flexible tube in a rigid array which includes static instability as a special case.