EST - Artigos de Periódicos
URI permanente para esta coleçãohttps://ri.uea.edu.br/handle/riuea/4779
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Item Efeito da variação da geometria do casco na resistência ao avanço e nos movimentos de uma barcaça regional(Universidade do Estado do Amazonas, 2024-09-29) Silva Junior, Jorge Artur Leite da; Hernandez Fonte, Jassiel Vladimir; Hechavarria Perez, Jose Ramon; Maia, Harlysson Wheiny Silva; Amiri, Mojtaba MaaliThe Amazon region has several inland navigation activities related to the transportation of cargo on river barges. However, there is still a lack of technical studies related to the hy drodynamic behavior of this type of vessel. In order to investigate the operational aspects of regional river barges, a comparative study was conducted, aiming to analyze several hydrodynamic characteristics of a regional barge hull. The effect of the change of the bow and stern hull inclination of a regional cargo transport barge on the hydrostatic characte ristics, ship resistance and motions was evaluated using simplified methods. Hydrostatic characteristics such as displacement, metacentric radius and height were analyzed. For the analysis of ship resistance, methods of practical use were evaluated (i.e., Holtrop and KR Barge), discussing the restrictions and limitations of each. Finally, the uncoupled motions of heave and pitch in regular waves were analyzed. For comparison purposes in each of these topics, a reference barge case was modeled, changing the inclination of the bow and stern of the hull, totaling four case studies. To perform the analysis, the soft ware Maxsurf and its utility packages Modeler, Resistance and Motions were used in the analysis of hydrostatics, ship resistance and motions in waves. Regarding the hydrostatic characteristics, study case 2 (inclination of 30° in the bow and 48° in the stern) and study case 4 (12° bow and 14° stern) presented better performance in relation to the standard case (17° bow and 21° stern), presenting a variation of 7.13% in cross-sectional metacen tric height for case 4 and -6.21% for case 2. Similarly, in the analysis of ship resistance using the method of Holtrop, case 2 presented variations between 13.7% and 39.3% and the case 4 variations between -6.7% and -25% in relation to the standard case. The KR Barge method overestimated the reference ship resistance values due to its limitations for practical implementation. For the significant accelerations in heave motion, study case 3 (14° bow and 17° stern) showed a variation of 2.17% and case 4 (12° bow and 14° stern) a variation of 4.56% with respect to the reference case, both operating at a speed of 1 knot. With the results obtained regarding river barges, it is expected that the work will add to the research on inland navigation in the Amazon region.Item 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 RamónIt 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.