On a Mathematical Model for the Hydrodynamic Interaction of Ships in Tandem Available to Purchase

The problem of ascertaining that floating ocean structures exhibit adequate dynamic behavior under the action of frequently taxing environmental conditions is of major importance to safe offshore operations. Many times, two ships remain close to each other at sea; one such situation occurs during the widely employed offloading operations, in which a shuttle tanker has to keep position near a production vessel (FPSO) for long periods of time against the action of wind, ocean currents, and waves. The dynamic behavior of two vessels in tandem has been investigated in numerous works in the past, but the vast majority of those works make use of uncoupled hydrodynamic models, that is, models that do not include any fluid interaction between the structures. In the present study, we propose to make a step towards the investigation of the influence of hydrodynamic interaction on the global dynamic behavior of two ships in tandem. To such end we propose, and produce validation results for, a novel model for the geometric parametrization and strength assessment of the wake generated by an FPSO under steady current. The model is based on first principles and makes use of the same kind of information already available for the calculation of hydrodynamically uncoupled response. In fact, one of the main guidelines in the development of this model is the preservation of the valuable knowledge and experience already accumulated in those previous studies. We present novel results concerning the fundamental aspects of the wake generated by a ship under steady current.