Flow-induced vibration of a flexible tube with squeeze film in an otherwise rigid tube array subjected to cross-flow

In this study, a mathematical model was developed to investigate the effect of the squeeze film on the dynamic characteristics of a flexible tube in an otherwise rigid tube array subjected to cross-flow. The vibration responses of the tube system were calculated to reveal the nonlinear dynamics of the tube system with squeeze film. The tube bundle’s bifurcation and post-instability characteristics were analyzed, and the instability mechanism was revealed, taking into account the effect of the squeeze film. The numerical results showed that the thickness of the squeeze film is a critical parameter affecting the instability and the dynamic response of the tube bundles system. The study found that oscillation instability occurs at the initial equilibrium position when the squeeze film thickness is large. Conversely, when the squeeze film thickness is small, static instability occurs at the initial equilibrium position, and the limited cycle motion occurs at a new equilibrium position near the boundary of the squeeze film.