An original applied study has been developed, concerning the analysis and the prediction of the hydrodynamic forces Which act upon arbitrarily oscillating bodies in the sea. The Morison formulations have been applied also for the case of constant drag and mass coeffiCIents, when the wake veloc1tles which are produced by the body motions in all the past histories are opportunely corrected; moreover the wake velocities have been here computed also on the basis of the unsteady turbulent theory, which is available from the existing literature. The predicted results have been compared with the experimental ones, coming from a deal of lab pendulum tests. The said tests have been performed both on single and on coupled cylinders, with particular care for the overall configuration cases and possibilities. Starting from the 1st case of square cylinders, the study has been after- wards generalized to the case of circular cylinders, more adequate - in many cases - to represent and to model the spatial and the physical reality.
The design of the majority of the offshore structures for offshore petroleum drilling and product1on operations requ1res a careful prediction of the hydrodynamic forces Which act on their components. Many of them are, in most cases, members having circular and other cross sections, with their submerged parts frequently close to the free surface of the water. In Chung (1976) as far as the floating structures are concerned constant values of the added masses have been considered, and also zero wave damping values (obtained for an infinite fluid). Among the first Chung (1977) published real comparisons of experimental added masses and wave damping coefficients with theoretical coefficients computed by the Frank's method, showing that agreements are much better for circular cross sections, and better for heaving than for swaying motions.