Nonlinear vortex-induced vibration analysis of a fiber-reinforced composite pipes transporting liquid-gas two-phase flow

Nowadays, pipelines are often used in marine engineering to effectively transport oil and natural gas due to their good continuity and high efficiency. However, the unwanted dynamics of the pipelines caused by the interaction between the external environment and internal fluid pipelines may affect their normal operation and service life. In the paper, we present a fiber-reinforced composite pipeline transporting liquid-gas two-phase flow to reduce harmful vibrations and investigate the present system's nonlinear vortex-induced vibration (VIV). Using Hamilton's principle, one can attain the dynamic equations governing the VIV in a fiber-reinforced pipeline that transports a two-phase petroleum and natural gas flow. The Galerkin technique is applied to discrete the governing equations from partial differential equations into a set of ordinary differential equations, and the numerical solutions are received using the Runge-Kutta methodology. Moreover, the exactitude of the theoretical model is verified by comparing it with published experimental and finite element results. Numerical results reveal the influence of internal and external velocities on the post-buckling behavior of the pipe. Moreover, the natural frequencies and maximum response displacements are discovered to be related to the parameters of two-phase flow such as slip ratio and liquid-phase volume coefficient. Besides, research has found that the axial tension significantly impacts on the VIV response of pipes in the supercritical regime, which means the maximum response displacement of the pipeline can be controlled by changing the tension amplitude.