Efeito da variação da forma do casco na resistência ao avanço e na geração de ondas de uma embarcação regional do tipo expresso

Abstract

The Brazilian Amazon has many regional vessels dedicated to the transportation of cargo and passengers. Currently, various types of regional vessels are built following previous experience, without carrying out analyzes that allow them to characterize their hydrodynamic and structural behavior using Naval Engineering methods. Three-dimensional modeling and computer simulations of regional vessels still have challenges to be addressed to develop more efficient and safer vessels. Seeking to contribute to this topic, this work presents a study of the effects of hull shape variation in some of the hydrodynamic characteristics, such as resistance to advance and generation of waves, of an Amazonian regional vessel. Due to the relevance of the longitudinal transportation of passengers, it was considered a high-speed regional expresso type vessel. In the first part of the study, computer-aided design techniques were used to model the ship three-dimensionally. Subsequently, the shape of the hull was varied systematically, changing the transversal position of the chine, to generate four different hulls. Considering the geometries generated and keeping the draft of the project constant, comparative analyzes of ship resistance, effective power, and waves generated by the ship were carried out, using Naval Engineering methods available in software for academic use. The results obtained allowed us to compare the effects of the variation in the hull shape on the hydrodynamic behavior of the vessel. Considering the invariable draft, the reduction in the transverse position of the hull chine in relation to the keel reduced the total ship resistance and the amplitude of the waves generated. This reduction in resistance was up to ~30% at the operating speed, under the simplifying assumptions considered, since the effects of this change on the stability and other parameters of the vessel design still need to be researched. The methodology presented can serve as an example to carry out parametric studies with other regional vessels, being possible to vary other geometric parameters of the hull with the software that was used.