Numerical Analysis on Pipeline Laying for Intake Deep Ocean Water

摘要

This paper is concerned with a numerical simulation of laying apipeline for intake of deep ocean water. An implicit finite differencealgorithm is employed for three-dimensional dynamic equations of apipe. Geometric nonlinearity and bending stiffness are considered andthe equation is solved by Newton-Raphson iteration technique. Thedynamic behavior of the laying pipeline is analyzed includingpretension, pay-out rate, and seabed slope. In the case of a flat seabed, a touch down velocity is fast at the initial laying stage due to pretension loss and then gradually approaches to a steady-state condition. For the flat seabed, the top tension also greatly decreases when the pipe touches down the sea bottom and then gradually approaches to a steady-statecondition. Meanwhile, when the seabed has a slope, the variation of thetouch down velocity is nearly regular because the pretension effect isnot large. The result shows that some attention needs to be paid when alaying pipeline touches down on a flat seabed.