Assessment of hydrodynamic properties of bodies with complex shapes

For the purpose of simulation of the offshore deployment of industrial modules in very deep water, two methods for assessing the inertial properties of bodies with complex geometries are proposed in this work. The first method is referred to as the frequency limit method and is a theoretical procedure using the widespread availability of seakeeping codes and the respective limits established therein to find the added mass, including the rotational inertia. The only prerequisite is that the body must have one plane of symmetry. Sets of results are published for the first time in graph and table format that will prove useful for designers. The second method is referred to here as the constant acceleration method and is an experimental method that calls for a well-controlled dynamometric car. Once constant acceleration has been applied to a towed body, this paper shows how to get the added mass for consistency in multiple runs. Both methods are applicable for deep-water deployment of a manifold, and the coherence between the two distinct methods is shown.