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Estudo de um absorvedor de ondas ativo para tanque didático. / Study of an active wave absorber for didactic wave tank.Michima, Paula Suemy dos Santos 10 October 2007 (has links)
Este projeto trata do estudo para implementação de um sistema de absorção/geração de ondas no Tanque de Provas Didático I do Departamento de Engenharia Naval e Oceânica da Universidade de São Paulo (PNV-EPUSP). As instalações já existentes incluem o tanque de provas, sensores de ondas resistivos e batedor de ondas do tipo cunha. Para a parte física do absorvedor, o sistema do servomotor foi disponibilizado pela MOOG do Brasil Controles Ltda. Dado que as propriedades desses equipamentos foram pré-definidas, os demais componentes foram escolhidos e projetados de acordo com esses parâmetros, levando-se em conta a compatibilidade com as características das instalações e a factibilidade de se adaptar e modificar os componentes para a realização de futuros ensaios com diferentes tipos de ondas. Tais componentes foram construídos com o suporte financeiro da Agência Nacional do Petróleo (ANP). O dimensionamento da placa basculante e a geometria do suporte do pistão são apresentados, bem como as caracterizações de cada item das instalações já existentes e do novo batedor de ondas destinado à absorção. Um algoritmo preliminar de controle é proposto e testado. Como houve a impossibilidade de se encaminhar o teste empírico do controlador no tanque do PNV, este foi executado na Yokohama National University (YNU, Japão). Os resultados numéricos mostram um bom desempenho do algoritmo, porém na implementação deste em equipamento físico, a análise dos testes mostrou que algumas melhorias devem ser realizadas para utilizações futuras. / This project presents the study for implementation of an absorbing/generating system in the Didactic Wave Tank I of the Department of Naval Architecture and Ocean Engineering of the Escola Politécnica of University of São Paulo (PNVEPUSP). The available facilities at the wave tank were resistance type sensors and a plunger-type wave maker. As the absorber\'s hardware, a servomotor system was applied, which was lent by MOOG do Brasil Controles Ltda., and the further components were designed and constructed with the financial support of the National Petroleum Agency (ANP). Since that equipment\'s properties were predefined, the constructed components\' geometry was decided concerning to the compatibility with the mentioned facilities. Also some attention was addressed to the requirement of being easily adaptive to modifications for later different kinds of wave experiments. The design steps of the new actuator and the description of the piston\'s support are shown, as well as the characterization of each item of the available facilities and new wave maker designated to be the absorber. A preliminary control algorithm is also proposed and tested. Since there was an impossibility of carrying out the controller\'s empirical tests in the tank of PNV, they took place in the Yokohama National University (YNU, Japan). The numerical results showed a good performance of the algorithm, however in the empirical tests\' analysis, some improvements were found necessary for future implementations.
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Estudo de um absorvedor de ondas ativo para tanque didático. / Study of an active wave absorber for didactic wave tank.Paula Suemy dos Santos Michima 10 October 2007 (has links)
Este projeto trata do estudo para implementação de um sistema de absorção/geração de ondas no Tanque de Provas Didático I do Departamento de Engenharia Naval e Oceânica da Universidade de São Paulo (PNV-EPUSP). As instalações já existentes incluem o tanque de provas, sensores de ondas resistivos e batedor de ondas do tipo cunha. Para a parte física do absorvedor, o sistema do servomotor foi disponibilizado pela MOOG do Brasil Controles Ltda. Dado que as propriedades desses equipamentos foram pré-definidas, os demais componentes foram escolhidos e projetados de acordo com esses parâmetros, levando-se em conta a compatibilidade com as características das instalações e a factibilidade de se adaptar e modificar os componentes para a realização de futuros ensaios com diferentes tipos de ondas. Tais componentes foram construídos com o suporte financeiro da Agência Nacional do Petróleo (ANP). O dimensionamento da placa basculante e a geometria do suporte do pistão são apresentados, bem como as caracterizações de cada item das instalações já existentes e do novo batedor de ondas destinado à absorção. Um algoritmo preliminar de controle é proposto e testado. Como houve a impossibilidade de se encaminhar o teste empírico do controlador no tanque do PNV, este foi executado na Yokohama National University (YNU, Japão). Os resultados numéricos mostram um bom desempenho do algoritmo, porém na implementação deste em equipamento físico, a análise dos testes mostrou que algumas melhorias devem ser realizadas para utilizações futuras. / This project presents the study for implementation of an absorbing/generating system in the Didactic Wave Tank I of the Department of Naval Architecture and Ocean Engineering of the Escola Politécnica of University of São Paulo (PNVEPUSP). The available facilities at the wave tank were resistance type sensors and a plunger-type wave maker. As the absorber\'s hardware, a servomotor system was applied, which was lent by MOOG do Brasil Controles Ltda., and the further components were designed and constructed with the financial support of the National Petroleum Agency (ANP). Since that equipment\'s properties were predefined, the constructed components\' geometry was decided concerning to the compatibility with the mentioned facilities. Also some attention was addressed to the requirement of being easily adaptive to modifications for later different kinds of wave experiments. The design steps of the new actuator and the description of the piston\'s support are shown, as well as the characterization of each item of the available facilities and new wave maker designated to be the absorber. A preliminary control algorithm is also proposed and tested. Since there was an impossibility of carrying out the controller\'s empirical tests in the tank of PNV, they took place in the Yokohama National University (YNU, Japan). The numerical results showed a good performance of the algorithm, however in the empirical tests\' analysis, some improvements were found necessary for future implementations.
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Wave-Cavity Resonator: Experimental Investigation of an Alternative Energy DeviceReaume, Jonathan Daniel 21 December 2015 (has links)
A wave cavity resonator (WCR) is investigated to determine the suitability of the
device as an energy harvester in rivers or tidal flows. The WCR consists of coupling
between self-excited oscillations of turbulent flow of water in an open channel along the
opening of a rectangular cavity and the standing gravity wave in the cavity. The device
was investigated experimentally for a range of inflow velocities, cavity opening lengths,
and characteristic depths of the water. Determining appropriate models and empirical
relations for the system over a range of depths allows for accuracy when designing
prototypes and tools for determining the suitability of a particular river or tidal flow as a
potential WCR site. The performance of the system when coupled with a wave
absorber/generator is also evaluated for a range piston strokes in reference to cavity wave
height. Video recording of the oscillating free-surface inside the resonator cavity in
conjunction with free-surface elevation measurements using a capacitive wave gauge
provides representation of the resonant wave modes of the cavity as well as the degree of
the flow-wave coupling in terms of the amplitude and the quality factor of the associated
spectral peak. Moreover, application of digital particle image velocimetry (PIV) provides
insight into the evolution of the vortical structures that form across the cavity opening.
Coherent oscillations were attainable for a wide range of water depths. Variation of the
water depth affected the degree of coupling between the shear layer oscillations and the
gravity wave as well as the three-dimensionality of the flow structure. In terms of the
power investigation, conducted with the addition of a load cell and linear table-driven
piston, the device is likely limited to running low power instrumentation unless it can be
up-scaled. Up-scaling of the system, while requiring additional design considerations, is
not unreasonable; large-scale systems of resonant water waves and the generation of large
scale vortical structures due to tidal or river flows are even observed naturally. / Graduate / 0547 / 0548 / reaumejd@uvic.ca
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