EST - Artigos de Periódicos

URI permanente para esta coleçãohttps://ri.uea.edu.br/handle/riuea/4779

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Efeito da variação da forma do casco na resistência ao avanço e na geração de ondas de uma embarcação regional do tipo expresso
(Universidade do Estado do Amazonas, 2024-06-22) Silva, Kleyphide Pereira da; Hernández Fontes, Jassiel Vladimir; Hernández Fontes, Jassiel Vladimir; Barreda del Campo, Eduardo Rafael; Cisneros, Edry Antonio Garcia; Hechavarría Pérez, José Ramón
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.
Estudo preliminar da estabilidade transversal e da dinâmica de uma embarcação regional que naufragou na Amazônia
(Universidade do Estado do Amazonas, 2024-07-16) Marinho, Hiago Francisco Andrade; Hernández Fontes, Jassiel Vladimir; Santander, Elvis Jhoarsy Osorio; Barreda del Campo, Eduardo Rafael
Several ship accidents have occurred over the years in the Amazon region, causing negative environmental, economic and social impacts. Although there are no details of the causes of all accidents that occur in the region, some shipwrecks have detailed accounts of what may have happened, making it possible to open discussion topics based on technical evidence. The present work presents a preliminary technical study of a vessel that sank in the Amazon region, analyzing some stability and movement factors with a possible contribution to the occurrence of the accident. The first phase of the study presents the problem of accidents on regional cargo and passenger vessels, describing several cases that occurred in the Brazilian Amazon. Subsequently, a shipwreck case study was considered to carry out the technical analysis, whose first stage of study consisted in generating a three-dimensional geometry that resembled the vessel's hull. Therefore, an intact transverse stability analysis was carried out, verifying the effects of different drafts and positions of the center of gravity. Finally, a critical stability condition was selected to evaluate the vessel's roll movement when subjected to the interaction of regular waves with different amplitudes. The results obtained demonstrated that inadequate combinations of draft and weight distribution can reduce the restoration capacity in calm water conditions. In this situation, some wave conditions, even those with low amplitude, can aggravate the problem due to amplifications of the roll movement and water shipping the deck. It is suggested that in situations where vessels operate with little freeboard, which are common in the Amazon region, there is a risk of shipping water, which can flood internal spaces if there is no adequate sealing of the deck, further compromising the survivability of the vessel. It is hoped that the present study can be extended to evaluate the possible causes of other accidents with regional vessels.
Levantamento de embarcações de pequeno porte comuns na Região Amazônica e estudo da resposta em ondas de uma embarcação do tipo voadeira
(Universidade do Estado do Amazonas, 2024-02-16) Almeida, Hector Reis; Fontes, Jassiel Vladimir Hernández Fontes; Fontes, Jassiel Vladimir Hernández; Santander, Elvis Jhoarsy Osorio; Barreda del Campo, Eduardo Rafael; Hechavarría Pérez, José Ramón
It is possible that the Brazilian Amazon has one of the largest concentrations of small boats in Brazil, mainly due to the lack of roads and the need for water transport of people and cargo between different cities. Many of these vessels, registered or not registered by the maritime authorities, can reach high speeds, making it necessary to further study to characterize their hydrodynamic behavior. This work aims to contribute to the classification of small, motorized vessels, typical of the Amazon region, and to carry out an analysis of the behavior on regular waves of a regional vessel known as “voadeira”. The main objective is to evaluate the possible movements that a ship of this type can present in wave conditions, without propulsion. These conditions may occur during adverse climatic events, common in the region, as they may generate eventual waves on the surface of the rivers. For the survey of vessels, the city of Itacoatiara, in the State of Amazonas, was considered as the representative location for the study. A voadeira type vessel was selected as a case study. The ship's hull was modeled using computer-assisted design and its response in waves was investigated using hydrodynamic potential theory methods. We investigated the effect of the variation of the angle of incidence of the waves and the vertical position of the center of gravity of the resulting movements. The results allowed determining the most significant movements, including the wave frequency that may cause them. The rotational movements show significant increases for different wave conditions. The methodology presented can be extended to evaluate other regional vessels.