Papers by raimundo pereira felismina
Renewable Energies Offshore, 2015
ABSTRACT Wave energy may cover in the future a significant share of electricity production demand... more ABSTRACT Wave energy may cover in the future a significant share of electricity production demand. This paper intends to be a contribution towards the use of this novel renewable energy source. Through finite element analysis (FEA), the influence of several characteristics on the structural behavior of a given floating point absorber wave energy converter (WEC) can be explored. WEC components can be, thus, optimized in order to reach the best structural performance, according with several specific characteristics. The FEA results demonstrated that the numerical model presented here allows the optimization of the WEC components according to its desirable applications.
This paper describes the design and analysis, from a structural point of view, of several buoy ge... more This paper describes the design and analysis, from a structural point of view, of several buoy geometries that could be applied to a floating point absorber Wave Energy Converter (WEC).
AIMS Bioengineering, 2014
In the last decades, the world energy demand has raised significantly. Concerning this fact, wave... more In the last decades, the world energy demand has raised significantly. Concerning this fact, wave energy should be considered as a valid alternative for electricity production. Devices suitable to harness this kind of renewable energy source and convert it into electricity are not yet commercially competitive. This paper is focused on the selection and analysis of different types of elastic materials and their influence on the structural behavior of a wave energy converter (WEC). After a brief characterization of the device, a tridimensional computer aided design (3D CAD) numerical model was built and several finite element analyses (FEA) were performed through a commercial finite element code. The main components of the WEC, namely the buoy, supporting cables and hydraulic cylinder were simulated assuming different materials. The software used needs, among other parameters, the magnitude of the resultant hydrodynamic forces acting upon the floating buoy obtained from a WEC time domain simulator (TDS) which was built based on the WEC dynamic model previously developed. The Von Mises stress gradients and displacement fields determined by the FEA demonstrated that, regardless of the WEC component, the materials with low Young's modulus seems to be unsuitable for this kind of application. The same is valid for the material yield strength since materials with a higher yield strength lead to a better structural behavior of WEC components because lower stress and displacement values were obtained. The developed 3D CAD numerical model showed to be suitable to analyze different combinations of structural conditions. They could depend of different combinations of buoy position and resultant hydrodynamic forces acting upon the buoy, function of the specific sea wave parameters found on the deployment site.
O uso de VANT (Veículos aéreos não Tripulados) em tarefas agrícolas como a pulverização de fitoss... more O uso de VANT (Veículos aéreos não Tripulados) em tarefas agrícolas como a pulverização de fitossanitários, a fertilização, a análise sanidade vegetativa e a sementeira, representa uma poderosa ferramenta da agricultura moderna. Países como o Japão utiliza VANT há mais de 30 anos em culturas com o arroz. Atualmente, uma em cada três taças de arroz consumida pelos japoneses foi semeada e tratada com recurso a VANT. Contudo, existem ainda muitos países nos quais os sistemas de agricultura utilizados poderiam evoluir fortemente com a implementação desta tecnologia. O custo de aquisição e de operação dos VANT apresenta um custo inferior quando comparado com os convencionais equipamentos pesados. Outra das vantagens é a segurança e a rentabilização da mão-de-obra. Todavia, o uso de sistemas/equipamentos passíveis de serem operados/deslocados e acoplados aos VANT, e.g. um semeador, um pulverizador, uma camara, não são tão comuns. Estes sistemas têm de estar conectados com o VANT quer term...
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Papers by raimundo pereira felismina