WAVE INTERFERENCE EFFECTS ON A DOUBLE-HULL SHIP MODEL, AS MEASURED BY GRAVITY DYNAMOMETER

The wave interference component of the drag of a double-hulled ship model as a function of speed and hull separation was investigated by means of a towing tank fitted with a gravity dynamometer towing system. Each hull was asymmetrical, with one flat and one curved side-an arc of a circle in plan. The results indicated smaller hull interference effects than given by the standard (parabolic) test hull results of Everest. The optimum separation ratio S L was 0.38-compared to 0.2 for Everest-while the resistance ratio Rw Rwin = wave resistance wave resistance at ∞ separation at optimum separation was 0.87, as compared with Everest's value of 0.52. These differences were ascribed to the differences in hull shapes tested-parabolic Everest hulls would produce stronger bow and stern wave systems-but were possibly influenced by the characteristics of the gravity dynamometer system used in this study. © 1990.