Ocean Systems Engineering Volume 6, Number 4, December 2016 , pages 363-375 DOI: https://doi.org/10.12989/ose.2016.6.4.363 |
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A hybrid method for predicting the dynamic response of free-span submarine pipelines |
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Tongtong Li, Menglan Duan, Wei Liang and Chen An
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Abstract | ||
Large numbers of submarine pipelines are laid as the world now is attaching great importance to offshore oil exploitation. Free spanning of submarine pipelines may be caused by seabed unevenness, change of topology, artificial supports, etc. By combining Iwan\'s wake oscillator model with the differential equation which describes the vibration behavior of free-span submarine pipelines, the pipe-fluid coupling equation is developed and solved in order to study the effect of both internal and external fluid on the vibration behavior of free-span submarine pipelines. Through generalized integral transform technique (GITT), the governing equation describing the transverse displacement is transformed into a system of second-order ordinary differential equations (ODEs) in temporal variable, eliminating the spatial variable. The MATHEMATICA built-in function NDSolve is then used to numerically solve the transformed ODE system. The good convergence of the eigenfunction expansions proved that this method is applicable for predicting the dynamic response of free-span pipelines subjected to both internal flow and external current. | ||
Key Words | ||
free-span submarine pipeline; vortex-induced vibration; internal flow; integral transform; pinned-pinned | ||
Address | ||
Tongtong Li: Institute for Ocean Engineering, China University of Petroleum, Beijing, 102249, China; College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing, 102249, China Menglan Duan and Chen An: Institute for Ocean Engineering, China University of Petroleum, Beijing, 102249, China Wei Liang: College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing, 102249, China | ||