Advances in the Resistance Estimation of Catamarans

The catamaran type hulls have been used since remote times;however they have almost always been restricted to minor ships. A massive growth of these kinds of vessels have been noted recently in the ferry industry, for sporting vessels and pleasure. The use of compaund materials and of aluminium, added to greater power, has allowed that the ranges of operation are developed at high speeds. One of the challenges which naval architectswho project these vessels must face, is to estimate with enough precision, the hull resistance to drag, a task which is not trivial at all because until today, a certain degree of uncertainity remains, particularly due to the interaction that is possible to notice between them. In the present study, the progress in the methods of evaluation of the drag in multi-hull ships, particularly that of a catamarans, obtained by computational fluid dynamics-CFD-, and through tests in a hydrodynamic testing canal carried out by the Universidad Austral of Chile. Besides, a method based on equations of regressions is presented for the calculations of the drag coefficient of waves for catamarans with round hulls in a regime of semidisplacement speed.