Research Interests:
Research Interests:
ABSTRACT The selection of the material regarding specific design of the stern tube journal bearings in vessels is critical taking into account the lubrication system, whether oil or water based, and the consequent lubricant leakage.... more
ABSTRACT The selection of the material regarding specific design of the stern tube journal bearings in vessels is critical taking into account the lubrication system, whether oil or water based, and the consequent lubricant leakage. Therefore, the present study examines the feasibility and the advantages of implementing water lubricated polymer shaft bearings instead of conventional white metal bearings lubricated by oil. The investigation method is related to the numerical model and the software application based on finite difference method and isoviscous model. Results, based upon data collected from three different types of actual vessels in service, have shown that power loss in polymer bearings is at least 6 times less than in conventional white metal ones indicating that polymer journal bearings are significantly more energy efficient and environmentally friendly.
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Environmental protection is finally an important issue and, due to previous sea contaminations and for economic reasons, merchant fleets are paying more attention to materials selection and to ship design. Taking into... more
ABSTRACT Environmental protection is finally an important issue and, due to previous sea contaminations and for economic reasons, merchant fleets are paying more attention to materials selection and to ship design. Taking into consideration that the propulsion system lubrication, whether oil or water, and the consequent lubricant leakage into sea is a critical problem, the present study examines the practicability and the benefits of implementing water lubricated polymer stern tube bearings instead of conventional white metal bearings lubricated by oil. The investigation method is related to a numerical model and a software application based on finite difference method and isoviscous model. Results, based upon data collected from two different types of actual vessels in service, have shown that power loss in polymer bearings is at least 6 times less than in conventional white metal ones indicating that polymer journal bearings are more energy efficient and environmental friendly.
Research Interests:
ABSTRACT The selection of the material regarding specific design of the stern tube journal bearings in vessels is critical taking into account the lubrication system, whether oil or water based, and the consequent lubricant leakage.... more
ABSTRACT The selection of the material regarding specific design of the stern tube journal bearings in vessels is critical taking into account the lubrication system, whether oil or water based, and the consequent lubricant leakage. Therefore, the present study examines the feasibility and the advantages of implementing water lubricated polymer shaft bearings instead of conventional white metal bearings lubricated by oil. The investigation method is related to the numerical model and the software application based on finite difference method and isoviscous model. Results, based upon data collected from three different types of actual vessels in service, have shown that power loss in polymer bearings is at least 6 times less than in conventional white metal ones indicating that polymer journal bearings are significantly more energy efficient and environmentally friendly.
Research Interests:
Resumo Este estudo consiste em mostrar o desenvolvimento e a aplicação do efeito degradê por meio de desenhos bitmaps para gravação a laser em madrepérolas visando um design de superfície adequado ao material e eficiente em sua função... more
Resumo Este estudo consiste em mostrar o desenvolvimento e a aplicação do efeito degradê por meio de desenhos bitmaps para gravação a laser em madrepérolas visando um design de superfície adequado ao material e eficiente em sua função estética. Para alcançar o objetivo foram, realizados ensaios de gravação com variações de velocidades, para verificar os melhores parâmetros. Os resultados foram observados com auxílio do Microscópio Eletrônico de Varredura (MEV), imagens de lupa estereoscópica e percepção visual e tátil. Esta pesquisa disponibiliza resultados que podem ser aplicados em escala industrial diversificando a criação de produtos na confecção de adornos e artefatos decorativos em materiais naturais. Palavras-chave: design de superfície; gravação a laser; madrepérola; materiais naturais. Abstract This study is to show the development and application of the gradient effect through bitmaps drawings for laser engraving on mother of pearl targeting a surface design appropriate to the material and efficient in its aesthetic function. To achieve this goal, engraving tests were carried out at speeds of change, to see the best parameters. The results were observed with scanning electron microscopy of aid (SEM), stereoscopic microscope images and visual and tactile perception. This research provides results that can be applied on an industrial scale, diversifying the creation of products in making ornaments and decorative artifacts in natural materials.