The study of float wave formation for the usage as heavy-duty catamaran bulbs

Abstract

The large cargo catamaran ferries can increase speed freight transportation on inland waterways. However, an increase of vessel's speed entails the growth in the heights of ship waves when the ship, which in turn adversely affects both the hydrodynamic characteristics of the ship itself, enhances wave impacts on the catamaran bridge and the ecological state of water bodies. According some scientific articles one way to reduce wave resistance of large catamarans may be deployment а a float-bulb between it hulls. Ship's wave and wave resistance depend on the shape of the float-bulb, so it is advisable to study the parameters of the waves formed first on the bulb in free flow, and then together with the catamaran. In this paper presents analytical equations for the resistance of the "float-catamaran complex", as well as formulas that also allow one to calculate the main parameters of the float-bulb. The results of numerical simulation are presented for the three ellipsoid's length: 29,2m (Fr=0,414-0,691), 14,6m (Fr=0,585-0,978) and 7,3m (Fr=0,827-1,383), ball d=1,76m (Fr=1,685-2,816). The characteristics of the generated ship waves is determined. Conclusions about the feasibility of modifying the float-bulb shape for heavy catamarans is given.