Instability Mechanisms and Stability Criteria of a Group of Circular Cylinders Subjected to Cross-Flow. Part I: Theory

Abstract

A mathematical model is presented for a group of circular cylinders subject to cross-flow. It is found that there are two basic dynamic instability mechanisms: instability controlled by fluid damping and instability controlled by fluidelastic force. Approximate closed form solutions of the critical flow velocity for the two mechanisms are obtained based on constrained-mode analyses. The model has identified the key parameters in the stability criteria and their functional forms and resolved the controversy associated with the empirical stability criteria.