Vibration and stability analysis of axially moving and spinning fluid-conveying pipes

An axially moving and spinning fluid-conveying pipe is a typical triply gyroscopic system. Under the combined effects of internal flow excitation and motion coupling, the system is susceptible to static and dynamic instabilities, which pose a serious threat to structural operational safety. In this study, the vibration and stability of an axially moving and spinning fluid-conveying pipe are systematically investigated. The coupled governing equations of motion are derived based on the Euler–Bernoulli beam theory and Hamilton’s principle, with the effects of axial motion, gyroscopic effect, and internal flow excitation fully taken into account. The resulting governing equations are then discretized using the Galerkin method, and the system’s complex eigenfrequencies are obtained to examine their evolution, stability characteristics, and time-domain responses. Furthermore, the effects of key parameters, including axial moving velocity, spinning velocity, flow velocity, mass ratio, and gravity parameter, on the vibration behavior of the system are examined in detail. The results indicate that the vibration characteristics of the pipe system are particularly sensitive to the axial moving velocity, spinning velocity, and gravity parameter. Also, the vibration response and instability behavior of the system are governed by the combined effects of fluid-structure interaction (FSI), gyroscopic effect, and axial motion.