An Experimental Investigation of Interaction between Adjacent Spans in Pipelines

摘要

Submarine pipelines in deep water face irregular and uneven sea floor. The installation of pipelines in such areas leads to large number of free spans. Such spans will be exposed to current and may experience vortex induced vibrations (VIV), and hence, also fatigue damage. Experiments with a flexible pipe model were conducted to understand the VTV response pattern of free long spans of high LTD ratio pipelines. One specific aim of the experiments has been to verify a hypothesis regarding transfer of energy from one span to its neighbor under given flow and structural conditions. The hypothesis was formulated on the basis of theoretical analyses, but had so far not been verified by dedicated experiments. The presented experiments give, however, a clear indication that such energy transfer takes place, and for some flow conditions result in increased response amplitudes, which are higher for interacting spans than for isolated spans.